Anon, I’m going to use this as a bit of a jumping off point so don’t get offended because this all isn’t necessarily directed at you but more of the collective “you”.
I don’t understand this idea that a lot of people seem to have that if two characters don’t spend enough time in canon together, people shouldn’t write fanfiction about it. Like, that is the whole point of fanfiction! You get to do whatever you want. You can pair whoever you please with each other because it’s your god damn story! If you want canon, read or watch the source material. You’re allowed to not like pairings or not want to read certain fics, but don’t act like your particular ship is any better because the characters exchange more dialog with each other. If anything, it’s the people who are coming up with these new relationships and writing these awesome stories that deserve more credit in fandom than the people that recycle scenes from movies or comics into fics.
Now, let’s talk about Clint/Coulson, shall we? You’re right, this pairing really came from no where. They said like two sentences to each other in Thor, a few panels in Fury’s Big Week and now there are over 3,000 Clint/Coulson fics on AO3. Regardless of what you think of the ship, that is fucking amazing. I mean, really. These people took two characters and created backstory and history and timelines and pretty much an entire alternate universe and they made it fucking work! And if you don’t think these are the same fans that generated so much love for a character that Marvel brought him back from the dead and gave him his own show, you’re a fucking idiot. Fans like the ones who dedicated time to writing story after story about Coulson are exactly the reason all of that happened and how can you not think that’s fucking awesome? They wrote fanfiction about Coulson being alive and it came true! I’m not saying that someone at Marvel is reading Clint/Coulson fanfiction and thought it would be a good idea, I’m just saying that it’s those kinds of fans that produce enough buzz that can make stuff happen.
And isn’t that kind of what we all want when we’re reading or writing fic? Don’t we secretly hope that one day maybe Steve and Tony will finally do the nasty, maybe Spock will just grab Kirk and kiss him, maybe The Doctor will fly into space with Captain Reynolds? Coulson fans got to see that. They got to see their fiction become canon. How can you not be happy for that?
Bottom line is that if you can write a good enough story, if you can make me believe that whatever you’re shipping works together in the universe you’ve created, I’ll enjoy it. But even if I don’t, I’m not going to bash someone’s personal creative outlet. Fanfiction is this totally awesome tool that anyone can pick up and use and create with and I’m not going to look down on something that makes somebody out there happy.
Are some pairings more realistic than others? Yes, but fanfiction isn’t about being realistic. It’s about doing whatever you want, making something you enjoy and sharing it with other fans who might like it too.