Of course, I'm sorry if that came across as offensive/rude, I thought it was clear I was talking about one of the possible cases.
No, not at all! Was just adding that to make sure people reading your comment didn't think it was only about fetishes (which there's nothing wrong with).
Interpersonal relationships, in-universe, though, are depicted as being fairly normal. So nonsensical pairings absolutely stand out a utterly out of character. Which is why comics of D.Va guzzling Mountain Dew, and McCree learning to ride a horse are funny to me, but Junkrat and Sym, or Mercy x (litterally everyone under the sun) make me roll my eyes.
But we know
almost zero about the characters' sexual preferences, attractions, relationship statuses, and so on. You can't say Junkrat x Symmetry wouldn't work with any more authority than I can say Mercy x Pharah would, because we've got not data to support either option. We know that one of the Overwatch characters is gay, and really, that's it. What if, say, Solider: 76 is the gay one? That then completely throws out every piece of Mercy76 fan art in some people's eyes.
Then again, it doesn't. As has been said constantly, the fan shipping stuff is about having fun with the pairing that you like. Who cares if it makes sense? If it doesn't to you, then don't download the art, and scroll past it when it's posted. I have zero interest in Mercy76, yet every bit of protesting I've said about it in here has all been in good fun, and I think some of the art that comes from that ship is pretty damn good. If people enjoy Mercy76, then more power to them, because their fun isn't in any way stopping me from getting Pharmercy art—and neither of those sides is doing anything to impact the game and people who don't care about shipping period.
If Blizzard starts catering to the shippers and making the game officially recognize certain pairings,
then I think there's room to complain about what's been done. Even then, though, we also don't know that Blizzard doesn't already have plans to make any of the characters romantically involved as more of the actual story is revealed. And it wasn't
me who put a Weekly Brawl into the game that featured nothing but Pharah and Mercy pairings.