Just because you ignore the footage, doesn't mean it doesn't exist.
I answer with two quotes from reddit, who summarize it pretty good:
Lovetoreader:
Okay idk what media people have been watching, but any time I heard someone cry about how we can never have straight male relationships anymore, I would love for you to look at GLAAD's media study that literally counts the amount of lgbtqia+ characters compared to all characters being created (I think it's US/western based) for the year. All of these ships that people cry about are RARELY actually canonical gay characters and it's still a major point of representation when queer characters are included at ALL in media in a meaningful and respectful capacity.
Okay but to Destiel specifically, i don't care if people ship it or not, do what u do. But to act like there was NO precedent for a romantic storyline is absurd. Supernatural is a show that RELIES on parallels heavily, and destiel falls into many of those major parallels (that i'll list in a sec.). While I totally agree that it wasn't planned from the beginning (shoutout to misha for stealin the show and becoming a series regular) it's something that clearly was played off of multiple times in the show, sometimes for laughs and sometimes in a more ambiguous way (but also spn writers, jokes are still canon, if everyone jokes about characters being in love that doesn't come from nowhere).
OKAY the parallels (yes i am a loser who is taking my time to do this, idc, it's my life). Some of these are destiel, and others are to prove that parallels (especially romantic ones) are already utilized on the show for storytelling purposes and that it shouldn't be limited to the straights.
John witnessing Mary's death on the ceiling vs Sam witnessing Jessica's death on the ceiling
Cassie vs Cas (and sam noticing how dean acts around both of them)
Sam seeing Jess everywhere after she died v Dean seeing Cas everywhere after escaping Purgatory (specifically a shot where the boys both see their partners out the window of the impala; also dreaming of them)
Lucifer using Jess's image to trick Sam vs Lucifer pretending to be Cas to trick Dean (and sam)
Dean dragging sam bodily from the building while jess burns on the ceiling vs Sam dragging dean bodily through the rift/portal thingy when cas is going to fight lucifer (which is a suicide mission)
Cain, Abel, and Collette vs Dean, Sam and Cas (Cain literally lists them and also crowley in the opposite order of how he suffered, from brother to lover etc.)
also collette only asking cain one thing (to stop) and then in the reverse crypt scene cas asking dean the same
Charlie losing her gf vs Sam losing Eileen vs Dean losing Cas (but nah just buds bein buds)
adam and eve splitting up and adam marrying an angel vs NEED I EXPLAIN THIS ONE CMON FOLKS
okay but the fact that the crypt scene literally got paralleled with the reverse crypt scene (and technically the rowena attack dog curse if u squint)
cas controlled by naomi almost kills dean
dean controlled by the mark of cain almost kills cas
literally every time an angel (or anyone i guess) asks cas to kill/betray dean and he's just like ✨no✨
the very touch of you corrupts when castiel first laid a hand on you in hell he was lost
i wont hurt dean, what broke the connection, i need you
the stench of that impala's all over your trenchcoat
you have to choose castiel its us or them
well guess what, he's dead too
cas defying the will of god vs dean defying the will of death (i mean not romantic inherently but cmON, especially when cas defies god specifically for dean)
bobby having to kill his wife multiple times vs cas having to kill copies of dean
cas returning from purgatory vs eileen returning from being dead
lisa and cas BOTH talking about wanting dean but being unable to have him
sibling parallels between Michael and Lucifer, Cain and Abel, and Dean and Sam
michael mimicking cas and casifer mimicking dean (besties that was WILD)
claire losing kaia and dean losing cas
i could go on and on and i'm sure i missed plenty, but i just sincerely doubt that a straight couple could have this much going on without being shipped. AND that if they WERE shipped, people wouldn't be whining about how we're making everything straight. double standards my dudes
conchested:
their arc was absolutely queerbait. the writers paralleled them with canon relationships, wrote in comments by other characters that suggest “more” between cas and dean (note: they’re the only pair i remember that get suggestive comments/jokes made about them consistently), emphasized the way dean and cas cared about each other (s13 when dean became severely depressed after castiel died, much like he did with sam though he didn’t try to bring cas back/sacrifice himself, but that could be him finally learning a lesson, until cas showed back up), etc etc., and then never confirming feelings between them. castiel’s confession was romantic, obviously, but it was never mentioned again. the most we got was dean’s “that’s not who i am,” to chuck in the next episode.
the writers played with our feelings because it got publicity, it kept people watching, but they never risked losing their original fanbase (even though making destiel canon would have gotten a lot more people watching, and been revolutionary in the entertainment world). they had so much potential, perfect opportunities to confirm the love story they accidentally-on-purpose wrote, and didn’t.
all this to say: i completely agree with you, and the fact that destiel is an argument in the fandom says a lot about the fanbase’s complex comprehension skill. they take everything at face value. if i didn’t connect any dots, i might be able to see their relationship as platonic.