>>58445032I was reading, and the reason for this is:
1. It's normal for mangakas to start in independent circles, and porn is a safe place to make a name for themselves and earn a little money before moving on to something serious.
2. H-mangakas have the curious combination of being cheaply paid, yet having so much talent, as well as an already established fanbase.
Also, the creator of Pokemon Colosseum has a manga where people fuck humanoid motorcycles.