I view the Linda/MC story differently, but at the same time I see your point. I do like the progression from "mom making her son breakfast, asking him to do his chores etc." and then a ladder of progress in the seduction/corruption. This formula works for a reason, and mainly that reason is that you get to be in control, your actions leads to the outcome. Also it makes the mom more realistic.
Why I think Linda is the exception that works:
Her looks are just so very well done. Not only is she gorgeous, 10/10 body and all that, she also looks slightly weared compared to some other ICSTOR moms.
She is a businesswoman, boss, married to an also (boring) successful man. She could have any man she wants, heck she could probably divorce Bob and seduce Justin Bieber or Brad Pitt the next day if she set her mind to it... but for some reason she has extremely strong sexual feelings for her teenage son. She also has the public fetish (& around Bob.. omg that scene <3)
This is her crutch at the start of the game. She had to start going to therapy to stop herself from having impure thoughts about her son (that book by doctor I.C. Stor is probably not helping LOL) . I find the combination of her looks, her occuption, social situation etc. combined with her urge to ravage her son (and really nobody else) is naughty as fuck. Altough we see the moms ultimately end up there in other games, they would fuck every other man in the world before their son prior to the corruption.
Take a mom from most of the other popular games and put her in place of Linda and this idea won't work as well IMO. Consequently, one could imagine a storyline where the MC gradually corrupted Linda to make her obsess about him... but for me that would make her appear mentally weaker, and her obsession would ultimately not be her own.
