Oh I agree.
But these books are trying to be both, but often are coming from people who aren't from the cultures they're inspired by.
And even though those works mentioned are inspired by Europe, there's still a bunch of Japanese tropes built in to each of them. Hellsing even has anime miko shrine maiden warrior priestesses, but makes them into Catholic nuns. That's a classic trope of taking the direct equivalent but saddling it with tropes and concepts you'd have from the author's culture.
It's not a bad thing, it's just a thing. Animesque can be fine. But if you're going to do samurai and ninjas or wuxia and triads and tongs, you better have creators on-board who actually have a connection with the culture you're inspired by, lest you just turn it into a gross caricature.
D&D lives on tropes sure, but it's very easy to go down into offensive stereotypes even when well-meaning, and cultural consultants are a must.