If Stepmania gets its own dedicated section so should LunaticRave/SSRMAX/Be-Pachi Music (IIDX simulators) and DTXMania (GFDM simulator)!
DTXMania at least, since I'm definitely going to start crafting some of my own DTXFiles over the next two weeks, starting with completing my Yakusoku file.

I doubt people actually use anything besides stepmania, see. :/ So I don't think this is quite a good idea.

Yeah, I myself don't use any simulators other than stepmania, which itself comes once in a blue moon.  If you could find many other people other than you who do use these other simulators and bring them here, then it may be relevant.  I'll commend you if you can achieve that though .