Forgive me for restating the obvious, but I was reading through an old post and it just kind of hit me in a way it hadn't before: One of hellers' most fundamental disconnects with the show (and media literacy in general) is how they try to insist parallels establish romance.
SPN used parallels to couples and romantic tropes a lot in regards to the brothers. But it was never meant as a signal that they were romantically in love or to tell you something you otherwise couldn't figure out. It was to underline what we already knew from the entire rest of the story about how they were the most important people in each other's lives. It used romantic relationships because that's a central status typically reserved only for romantic relationships - that was part of the point.
Let's take an example or two. Dean compares himself and Sam to Jesse and Cesar from The Chitters. After interacting with them for a while, Dean is like, 'Haha, you fight just like brothers, almost as bad as Sam and me' and they say that it's more like an old married couple. This is Dean comparing an exact thing that actually happens between him and Sam, silly petty bickering, to something that exactly happens between a married couple. Likewise, let's take Dean's expression and the script note he's thinking about Sam's close call in Red Meat. Michelle is talking about watching the man she loves die and how nothing can be the same, and Dean is thinking about how he believed he lost Sam earlier that same episode and reacting to what she's saying. No one is under the impression that these are signposts telling you for the very first time that Sam and Dean are weirdly, claustrophobically close in a way that compares to romantic couples. They're quick moments which draw an underline on what you already know from the way they've acted towards each other for the entire preceding (and following) length of the show. If you cut either of those moments? It would change nothing about what we understand of Sam and Dean's relationship, because that's how using parallels in storytelling actually works.
Hellers want to insist that romantic couples and tropes being parallels to D/C in and of itself proves that D/C is romantic. Why else would SPN use couples and romantic tropes?!? Well, because SPN does that all the fucking time, maybe? Which is even before you get into how superficial the basis for their supposed parallels typically are.
Let's take an example or two. Hellers want to insist that Dean and Castiel were paralleled to David and Violet from Bloodlines because and I shit you not, one of them wore a tan coat. As well as the absurdly generic dialogue line, "I was there, where were you?" being used both in the backdoor pilot and in 6x20 by Dean. Aha! David and Violet are clearly stand-ins for Dean and Cas, and they were planning to run away together, so D/C is clearly romantic, BOOM! Except literally nothing about Dean and Castiel's actual relationship lines up with that. In no sense were Dean and Castiel ever planning to run away from their families together - not at the point where Dean was calling Castiel out for pretending he didn't know where Dean was if he really wanted advice or otherwise. Unlike the actual parallels with Sam and Dean, there is no underlying narrative base. Likewise, hellers want to insist that Castiel is Dean's Colette. Aha! Cain said Dean is living his life in reverse, and he killed Collette last and his brother first, so since he said Dean would kill Castiel before Sam, Castiel=Colette, and Colette was a romantic partner, so Dean lurves the angel! BOOM! Just for the sake of being pedantic, let's break this nonsense down one more time. Cain lists Crowley as well as Castiel as people Dean will kill before Sam. Collette was special to Cain because she saw everything he was, never gave up on him, and was able to get him to drop the blade. Which is literally what Sam does during the time Dean has the Mark - meanwhile Castiel tries to get Dean to not go and slaughter the Stynes and fails and is ready to give up and kill Dean after he goes demonic. Which doesn't even get into the part where ... Cain is literally just wrong in telling his little fairy tale. Dean is not him. When given the choice of killing his brother, Cain does it. When given the choice of losing control, Cain does it. Dean tries to get Death to shoot him into outer space and then kills Death rather than actually kill Sam. Dean and Dean's love for his brother are both far stronger than Cain is capable of understanding. So the parallel life thing? Is fundamentally hooey anyway. Again, there's no narrative there for a parallel to be drawing an underline on because none of their cobbled together meta resembles anything going on in the actual text. That's not how storytelling uses parallels or any other kind of subtext, by creating something entirely separate and expecting the general audience to decipher it. Though it's no surprise they try to insist that a show would do that, because they have nothing else.
TLDR; Their entire argument is that a comparison to a romantic couple makes two other characters' relationship automagically romantic because reasons. Which even putting aside the lack of validity in their parallels ... continues to be a boldly idiotic statement given the number of actually textual comparisons the show makes between Sam & Dean and romantic couples. Again, it's no wonder they freaked the fuck out over that forehead touch, because they very fundamentally refused to understand what SPN was actually doing on literally any level.