She's normal in the context of the game world. A world where "powerful people" "destroy" famous executives and make them into sexual slaves, where random men offer 10 dollars for blowjobs to the downtrodden. Every character that has the slightest advantage/power over another will use it for sexual blackmail. You ever seen a "living mannequin" where you're allowed to sexually abuse her? I haven't. Where a secretary wields insane power over people making them do all kind of crazy shit and somehow Monica isn't tame compared to that? Did Monica ever demand people eat her pussy and stuff like that before?
The world that the dev has created is full of abusive manipulative assholes and she's just one of them. It makes the whole point of her being a bitch moot since everyone is a fucking bitch. Like cmon, even the fucking kid is a sexual maniac and a teacher has no problem blackmailing for sex. Don't even get me started on the Marcus jail scenes.