This, and the part where he says "certain historical accounts are exaggerated." I'm fine with a narrative presenting things as not being quite what was stated on paper, but there is a certain point where "history is a whitewash" and "oh yeah, this thing actually happens this way" become contradictory to each other. It doesn't necessarily need to be brainwashing, but a corruption of the self is an equally credible concept that would still allow written lore to be "incorrect" in some cases while maintaining its integrity. Telling us outright that "yeah, the lore is likely wrong here and these women are just wanton sluts with a particular preference for certain things" feels like a cheap cop-out.
MGD I feel hides a ton of its waifu stuff in the background. You can access it, but none of it is ever necessary to complete a dungeon or finish the main story. It also helps that the game does its best to set your goal and let you reach it at your own leisure.
MGQ isn't grimdark fantasy, though? I'm curious if those people who call it grimdark have ever read a the genre. Grimdark settings are bleak and dystopian, full of disturbing imagery. I would say Shrift fits the genre perfectly. MGQ is more a fantasy setting.
The argument that "this is a blank setting" doesn't really hold up. Plenty of stories have already done this and have handled it much better by making the supporting cast and setting do a lot of the heavy lifting. It feels like an excuse at this point to hand-wave any narrative flaws with "well, it's a blank protag in a blank setting."
I feel like you're confusing MGQ and MGE. In MGQ, you can learn magic and even sword skills that put you on par with monsters. It's also not a common occurence in MGQ to be raped outright by wandering monsters. They're largely sensitive to high quality semen, a thing the series makes fairly clear from the get-go. You also have places like Happiness Village and a few of the kingdoms on the central continent where monsters aren't just peaceful, but co-exist with Human's. You could argue that yeah, there are the more aggressive ones like in Insect Village, but why would you willingly venture to a place where everyone says you're gonna get messed up?
The vore content is fairly low, too. Some species of monster girls do eat each other, but that's more a survival thing due to a lack of men engaging with those places. And yeah, there are some monster girls who do vore the males, and that's mostly resolved by the end. Honestly, most of that stuff feels less fleshed-out than the larger setting and feels like it was just added to justify variety.
Wrong, Luka only learned everything he learned because:
1 - he was trained by the monster lord
2 - he had help from the spirits
3 - he is descended from a legendary hero
4 - he is the son of the strongest seraph
These factors were what made Luka strong, humans can seize magic, but it is something extremely rare and difficult, it is not the same in Paradox, where seizing magic is easy. in the original VN universe, it's so hard, you'll be an old man when you have quality spells in your arsenal.
And the sword techniques, as I said, without the "protagonist hacks", you will hardly be able to fight anything outside the continent of Ilias.
MGQ is an EXTREMELY unbalanced universe where you are destined to be weak, simply because you were "born without protagonist hacks".
And ok, not all girls devour men, but 80% of them enslave you, or drain you to death.
And, at no point did I say MGQ was grimdark, it most certainly isn't.
But if you look at the game's various possible endings, you realize it's a lot darker than it looks.
For example, in one of the endings, Alice definitely plans to destroy humanity (after you abandon her instead of helping her at the beginning of the game).
She eats Luka alive and mocks him when he challenges her in the cave.
Alma Elma devours him, simply because yes, and because "she likes to devour people"
And several other very dark endings.
With all that said, I repeat what I said before:
go to a world where I am weak, helpless, and can easily be killed or devoured by any monster(MGQ)
go to a world where i can learn magic, get strong, and get a wife(MGE)
I think the choice is pretty obvious