What do you exactly mean by "horrible" Touhou fanfics? Are you referring to fanfics that are hard to understand? ones that are riddled with plot holes? or something else entirely? There's a fair difference between something that is so bad it's good (schlocky) between something that is just bad and doesn't provide any entertainment value at all. I've seen a few stinkers throughout my time of just scrolling through Ao3 but once I realize they're just bad I roll my eyes and drop it so I can't really recall any that were notable at the moment.