I'm not sure, but I think the whole concept of 'the game' started by either a touhou comic, or a rewrite of a touhou comic. probably just that one page though. also, advent cirno.
oh, and alot of the Mugen Touhou characters are either half-assed, completely made up, or unavailable. one of the biggest hate factors for me was the fact that some dick was stupid enough to fake a Satori Komeiji character as an april fools joke! RRRAAAAAAAAAAAAGGGEEEEEE!!!!!!!... Seriously, though. Other than that, the touhou fandom doesn't bother me.
what DOES bother me is that ZUN seems to have a complete refusal to involve any shota in Touhou whatsoever. I mean, there are plenty of loli's some are more pubescent than others, but their loli none the less. and the only men that ARE in Touhou are either really old (physically), some random pet, or the owner of a random shop!!!!!! I WANNA FIGHT A POWERFUL SHOTA DAMNIT! YOUKAI OR NOT!!!!!!!!!
okay... I'm done.
oh, you may have guessed, but yes I am a Satori Komeiji fan. But my name is also the name of one of my many characters, who is a Satori-like being from- well, that would be going off topic.