just read "cas told them about the civil war in heaven and dean and sam didn't care at all" 1. sam was soulless so i think he gets some slack before he was re-ensouled, 2. dean kept asking to help and cas said no
Cas did not start out the show shy about asking Dean for help. He started the show with almost no sense of personal boundaries, flying into bathrooms or calling in the middle of the night and telling Dean, "I need your help". When Cas needed help in season 5, he was always direct about it. When Cas didn't need help and considered involving his human friends to be an inconvenience that would slow him down, he would disappear without a word, popping in and out of the room. So in early season 6, when Cas keeps popping in and out of the room, the signal he is sending to Dean is, "Your presence at this moment would slow me down. When I need you, I'll let you know." The funny thing is, Dean really doesn't like this behavior from Cas. He likes to know what's going on, and his frustration with Cas refusing to communicate is rather present in 6.03 and 6.06 (the first two season 6 episodes Cas appears in).
Getting Cas to even tell them there was a civil war on in 6.03 is like pulling teeth. Cas keeps flying away then flying back in, giving vague, frustratingly clipped answers. Dean is clearly irritated that Cas won't stand still long enough to give him a straight answer. Finally when they get the jist of the situation out of him:
DEAN: Cas, why didn't you tell us this?
CASTIEL: I was ashamed. I expected more from my brothers. I'm sorry. Now I need your blood.
Note that at this point, they're already working with Cas and helping him. Cas has already told them "I need your help." Their missions happen to align, but Cas is trying to find the weapon Balathazar stole and Cas wants to track it down and demands Sam and Dean's help, which they give to him (though soulless Sam is pretty pissed about being ignored for over a year). Dean gets this one moment of vulnerability out of Cas where he admits that he's been avoiding them out of shame, then Cas immediately breaks that tension by grabbing Dean by the wrist, yanking his hand over a bowl, and slicing his palm open without asking. Cas does not want to talk about what he is doing or why, because he knows if he stops for an instant (especially for Dean) he's going to start questioning some of the choices he's been making, and he can't afford that. The whole episode he's darting around place to place, pushing them around wherever he needs all of them to be, and makes himself as unapproachable as possible, controlling the means of communication and the entire situatiuon. The moment that Cas solves things with Balathazar (with Sam and Dean's assistance) he disappears before Dean can ask a single other question, then goes radio silent for weeks, until 6.06 when Dean prays about another angelic weapon (a thing Cas needs for his own purposes) then Cas shows up again. He makes it clear he needs the horn. He shares another small moment of vulnerability, while at the same time conveying that he is overwhelmed and busy.
DEAN
What happened to you, Cas? You used to be human, or at least like one.
CASTIEL
I'm at war. Certain... regrettable things are now required of me.
And Dean actually shows that he is thinking about what Cas needs, by turning away from Cas's questionable actions (torturing a child in 6.03) and straight to questions about the horn Cas needs.
DEAN
And Gabriel's Horn of Truth? That's a real thing?
CASTIEL
You've seen it?
DEAN
We think it's in town. Something's forcing people...
Sound of angel wings fluttering. CASTIEL has left.
DEAN
Oh, well, you're welcome!
Again, instead of truly including Dean in the why or how, Cas flys off without answering questions. He doesn't actually leave space for Dean to become a part of the situation in any other capacity than the limited ways Cas allows, because Dean's presence would be inconvenient.
Dean is also Not Doing Well in 6.06. He spends the entire episode scared and on edge around Sam, drinking to cope with being in the same room with him, being told by Sam and Bobby that he is crazy, an episode after being assaulted by a rapist and being unable forget Sam watching and smiling. We know he's been sending Cas increasingly frantic prayers out of concern that his brother is possessed by Lucifer (which would also be a big deal on the grand apocalyptic Raphael/angel front), and Cas hasn't answered him. Dean's clearly stung when Cas shows up in 6.06 only because Dean mentioned a weapon Cas needed. After everyone minimizing and ignoring his concerns, Cas is just one more person in his life doing the same, and if you willfully ignore what Dean is going through, you can come away with the conclusion that he's being entitled in 6.06, but if you pay even the slightest shred of attention to exactly how close to a full blown emotional breakdown Dean is in 6.06... it's not hard to see why he isn't in a space to do much more than put his own needs and concerns aside and ask Cas what the weapon he needs is, and to be stung when even that attempt to relate is rebuffed by Cas immediately flying off, with an added implication that Dean's weeks of emotional distress do not matter to him. Cas does come back, and observe Dean's clear distress, and promise his aid with Sam, and Cas makes good on that promise in the following episode, and Dean relies that promise in 6.07, but also clearly receives the "I am spread thin and cannot help you with anything" message that Cas is laying down by the end of the episode, and endeavors not to bother Cas.
It's actually soulless Sam who contacts Cas in 6.10, tricking him into showing up by claiming to have—ding-ding-ding! you guessed it!—an angelic weapon Cas can use in his war. And Cas quickly realizes that his friends and his business partner are about to kill each other, and involves himself to prevent either party from coming to harm by staging Crowley's death.
From 6.07 to 6.10, Cas uses Sam and Dean in his war effort. They just don't know that. Crowley coerces Sam and Dean into working for him and Cas, with Cas as the silent partner in the alpha-gathering business that Sam and Dean don't know about by Cas's design. Cas has no need to come to them and ask for help because they're already in fact helping him, doing exactly what he needs them to do. From Dean's perspective, unaware that Cas is involved with Crowley, Dean's avoiding burdening his busy friend with the King of Hell—someone Dean might have asked for help with in a different setting. And Cas can come to him if he needs something. He has no reason to think Cas won't come to him for help, because that's the only reason Cas showed up at all in 6.03 and 6.06—because Sam and Dean had something he needed.
6.10 is the longest stretch of time Dean and Cas spend together since the start of the season, and it culminates in Dean telling Cas he's there for him, and being told he can't do anything to help (which is what's been communicated by Cas's silence and flighty behavior anyway).
CASTIEL: Crowley was right. It’s not going well for me upstairs.
DEAN: If there’s anything we can do –
CASTIEL: There isn’t. I wish circumstances were different. Much of the time I’d rather be here.
DEAN: Look, Cas, we know you got a steaming pile on your plate. There’s no need for apologies. We’re your friends.
In this interaction, they're also both trying to apologize to each other and dispell the tension that was present from 6.06-6.07. Cas pretty much says he wishes he could just spend all his time with Dean (if that wasn't already clear from Cas lingering around their motel watching TV while a war is on). I.e., if Dean was under the impression during 6.06 that Cas did not care about him and that's why he ignored his frantic prayers, Cas wants to reassure him that that isn't the case at all. In turn, Dean tells Cas that he understands that Cas is busy, makes it clear that he is not hurt like he was in 6.06, and makes it clear that he's there if Cas needs him.
It isn't that they don't care about each other. It's that neither is in a mental space to support each other very well emotionally for the first 1/3-1/2 of the season, and Dean actually is helping Cas—he just doesn't always know it, because Cas doesn't want him to know. Cas and Balthazar use Sam and Dean again (as bait for Raphael and Virgil) in "The French Mistake" without their knowledge. All this secrecy serves to protect Cas's reputation among his friends and prevent the inconvenience of his allies (including the angels who also don't know what he's really up to) protesting how he runs things.
Like I think people really re-write season 6 Castiel into someone who was sulking, hands shoved in his pockets, kicking rocks because awww shucks he could really use Dean's help but Dean didn't care, and Cas was doing sooo many things for him. But that's not really what happened. Cas did Dean exactly one requested favor—helping with Sam in 6.07 (then maybe his brief appearance in 6.12?). Other than that, everything Cas did with Dean ultimately served his own interests. Cas did not fail to make Dean useful to him. He just didn't always want Dean to know how he was being helpful or that Cas was involved. That doesn't mean there weren't ways they hurt each others feelings, or that Cas had no reason to ever be stung (I think it's clear he was irritated with Dean in 6.07 for example) but I think the fandom take on the whole season comes off pretty warped because of a failure to re-examine some of these interactions with the knowledge of what Cas is actually up to and how he's intentionally hiding things and is actually using Dean the whole season.
