Yeah, actually... don't really understand it that. It's a third person porn game where YOU as the player determine some of Jason's actions.
And you watch through his point of view. That's the point of the game and why it's designed as third person, not first person.
Never (at least not in the near future) will porn visual novels become fully games, nor fully movies. For many reasons. Sadly or not.
And regarding the mom/sec scene.. the fact that Jason isn't directly involved doesn't mean he isn't involved at all.
After all, it's kind of a fetish, isn't it? Like many others it has its supporters and haters.
EDIT: now I think… the next things ppl could say are “I want to kick her in the face! Why Jason just slapped her?!?”. Or… “I want to talk to her, not rape her! I don’t feeling it like playing!”
and that.. here is the hard part. Because it’s impossible to satisfied everyone’s needs and fetishes, the author’s/dev’s job is to make the game interesting enough to satisfied as many players, as possible.