actually all those anime was not made by the official at all was made by fan and also Touhou started with a game instead of anime and popularized by game instead of anime/cartoon so yeah
Oh well Anime is basically "Japanese Cartoons" Literally, but if you want to put it another way you can say "Japanese Animation" or as most call it Anime. (But you probably already know that.)
You do know if it wasn't for it's popularity in porn games RPGmaker would have gone tits up (pun intended) long ago? Enterbrain and even Kadokawa have straight out acknowledged that numerous times over the years.
If the engine is so good a lot of developers would do other types of games and not porn. If developers don't do games in this engine is because they are stupid and avoid the engine for be an "exclusibly" porn engine or because there are better or prefered engines for them, like Unity or Unreal, and those engines has porn games too. So....
was made by fan
and also Touhou started with a game instead of anime
and popularized by game instead of anime/cartoon
so yeah
(But you probably already know that.)
its a shame they waste a good engine for pornographic shit