It used to be rad. That autism you speak of was a good thing. Users like that created a very structured, logical protocol for describing the "theory of entertainment". It was organized in a much more logical way than Wikipedia in fact. At some point their forums got inundated with radfems and otherkin and they started focusing on the "community" over everything else. Focus on building a community meant you had to communicate on the forums and agree with the dominant politics (anti-hate-speech and such) to have any sway in editing. Otherwise your edits could be undone. I had no interest in that and left. I could see what it was turning into. Now when I want to look up tropes in media I usually look at competing wikis, but those are usually full of ads and have a very ugly UI.

I've often considered creating my own wiki-alternative or distributed database format, and if I were to do so it would be much closer to something like TVTropes than Wikipedia. Though I'd try to avoid the thing where someone "fixes" an error by replying with a bullet point, and then someone else replies with a second level of bullet points, and so on, ad infinitum.

Correct. To prevent downspiraling you need active moderators and that means you need to pay someone, which means the site needs to be profitable