I think they're "subby" because a lot of men are discontent with hegemonic masculinity being the prevailing viewpoint on how men are viewed and the expectations that Society has for them. Subsequently, anime offers an alternative to the hyper-masculine media that are the norm in mainstream society (i.e. sports, super hero movies, video games), as there are quite a few dominant females in anime. The dominant females allow them to fantasizing about not having to be in control all of the time.
It’s interesting to me, because i remember hearing that high ranking executives tend to like being sexually submissive because it’s a break from their normal life.













