Mpreg while a bit strange to me, is fine enough. People want kids and a happy fantasy. So I get it. I just don't get why Omegaverse content has rape baked so heavily into it...and weird "justifications" for the rape.
Rape fiction as an outlet for internalized misogyny I understand well enough (though I am not a big fan of it either), and I don't think it's coincidental that omegaverse stuff is (from my limited delving into the medium) written and read mostly by women.
That said, the justifications built into Omegaverse creep me out. At least most overt/explicit rape stories are forthright that their content is about unacceptable behavior; I'm more creeped out by the stories that try to sanitize it.