the sam and jack parallels go fucking crazy. they were both born "evil" (being lucifer's vessel/kid) but despite it all tried to be good. sam grew up thinking he was a freak and a monster, and then having those fears confirmed with the demon blood, just to have dean turn on him and call him a monster!! then when jack comes around, his birth kills cas, like how sam's kinda killed mary, and dean's all ready to kill jack and lock him in a box! i love dean, but these were not his finest moments. not to mention, both sam and jack lost their souls!!! they're the only two main characters to have that happen to them (besides that one prophet but he was meh so). sam and jack were both born with a bad fate, but if there's one thing supernatural taught us, it's that you make your own destiny. and that's exactly what they did because both sam and jack are good people and they did save the world!! it just makes no sense for dean to have gone through the demon blood with sam, and then hate jack because he's lucifer's son.
wait a damn minute. did dean hate jack because he was lucifer's son? ik later on it was because he killed mary, but he was on team Find A Way Everyone Survives when kelly was first pregnant. dean only started hating on jack when cas ran off with kelly after the fight with dagon, where unborn-jack used his powers to help cas kill dagon. that means dean was hating on jack because he "took" cas away. but i definently remember dean saying something about not liking jack because he was lucifer's son. omfg spn writers should have figured this shit out before making it canon. like the spelling of cas' name. idiots. anyway, dean thought that jack used cas like a puppet, which is dean's greatest fear (losing his loved ones beyond recognition), so ofc he started hating jack for it. but come on cas, the lack of communication skills and abundance of self sacrifice!! cas decided jack should be born with all his powers and immediately runs away to raise jack on his own, with pure intentions ofc (protecting sam and dean), but poor execution. if they just talked all this shit out, so many problems would have been avoided. wait, what did this post start with? the similarities between sam and jack? only supernatural can do this to me. ✊️😔