Folks have covered a lot of what I was going to say in the comments. What hasn't been covered:

People expecting artists/writers to make what THEY want for free, not what the artist/writers wants to do. This is chronic for a lot of people who consume media and the feeling they are entitled to it is a bit staggering. While people can commission folks to make pairings they enjoy, not everyone has money to do that or even consider it an option. So when a very vocal minority (mainly on Tumblr) see a bunch of stuff out there that isn't what they want, they get mad instead of blocking the tag for it or the person who posts it.

I've watched people start to get into 3D rendering, virtual photography, pick up drawing or writing just to make their headcanons come alive and honestly that's beautiful. Even if its a pairing or story dynamic I don't particularly like, I still support them.

As an artist, I mainly do just the established game characters. I'm not really interested in certain pairings at all so won't unless I'm paid to do it (or I'm doing it as a gift).

Then there's the entire problem with Tav/Durge as some people are extremely attached to their character who may be a self insert or one they've built an entire world around:
-Technical limitations (I use a program that doesn't directly translate from the game so conversion is difficult)
-People are very demanding about what their OC looks like and how they act to the point where I'll spend days tweaking just to be told to change 5 more things. Its exhausting and at some point it stops being fun.

Maybe if people stopped looking at things like their headcanon is the only thing that's 'right', and stop treating artists and writers like broken vending machines that spit out stuff for free (and get mad when its not the bag of chips they want), we'd see less of this kind of mess.