"Quasi-realistic" is another way of saying "not realistic".
And it's not about whether a particular setting is or isn't 'okay'. If everyone in the group is happy with things, then by all means, set your game in Aggressively Unrealistic Medieval England and deviate from real history all you like. Port over a thinly-disguised version of GoT. Heck, run a strictly traditionalist game of Murder-Hobo Lords of Gor if that's what the GM and players clamor for.
But it's disingenuous to take a vastly unrealistic setting - cherry-picking bits here and there of "medieval Europe", slapping in new ones that never existed, and excising realistic elements that are boring or distasteful - and then insisting that elements A and B are there because realism demands it. As you note, it's a fantasy setting. So when a GM is happy to have wizards throwing fireballs, open borders, and a distinct lack of enforced monotheism, but insists that women can't be fighters or a lifted skirt clouds men's minds without fail or consequence, well. That's not actually a game with a historically-accurate setting. That's a game where the GM wants particular gender roles, but won't cop to it, instead letting History take the rap. (Poor History!)
Turning back to the actual subject of the discussion: it's a little difficult to get players to stick around for a game when the game itself, or its setting, takes away from their fun. And for rather a lot of people, "your PC is going to have to put up with the same crap as you do in real life! because realism!" is not something that makes a game sound like a fabulous way to spend a weekend.
Yep. Also...like...the extreme sexism of the general understanding of medieval Europe isn't even all that accurate, especially as a model of how the world has always worked, everywhere. That just...ain't a thing, folks.
If you married a woman in Scandinavia, in 800 AD, she could be the one who technically owned the home you share, she was legally and culturally still part of her family, she could divorce you with relative ease, the kids are hers at least as much as yours, maybe more, she could inherit property, speak at the Thing, rule a kingdom, or fight for a lord. That last one didn't happen as much as recreationalist like to imagine, but it happened, and there is no evidence of any rules against it, or stigma upon it.
Druidic Celtic lands were similarly egalitarian-ish. Certainly moreso than late medieval society, or America circa 1800 AD.
those are both societies from which big standard DnD draws inspiration.
and even later on, a lot of the "rules" were not as strict as we often imagine. Most of them could be flouted by anyone with the right sort of panache. Look at Mademoiselle Maupin*, for the best example ever. She didn't care about the silly gender norms, so she ignored them openly, and did it with such charm and style that she was celebrated, rather than stigmatized. Surely PCs are at least as cool as she was, when she first set out into the world.
Not height of her Opera career, level, of course. I mean, not many PCs are so cool they can duel the jerk in the opera production, then sleep with him, then headline the 17th century France equivalent of Coachella.
But maybe they are, "take the holy orders because your girlfriend got stuck in a convent, set something on fire, Sneak your gf out of the convent, shack up with her for a while, then go sing insults at d-bags in taverns and duel the ones that get in your face about", cool. Maybe.
*
https://en.m.wikipedia.org/wiki/Julie_d'Aubigny