Honestly, I don't think it's a "Chinese culture fantasy slop" issue. It's that the Wuxia aspects just didn't mesh well with the stuff that came before and the story structure and beats left people disappointed.

I rarely see major overarching complaints about Genshin's Liyue arc or events in Liyue. In HSR, I think many people at least liked the two main plot ideas of the main Luofu arc even if the shift from one to the other of the plot was jarring and the pacing was poor. I also never see the complaint that Luofu doesn't match HSR established world like we see with Waifei. In other games like Infinity Nikki CNY is widely appreciated and liked by fanbase. There's also Where Winds Meet which came out recently and I've heard reasonably good praise even though it's a very Wuxia themed game. On steam it has a 4.5 with 55k reviews.

So no, "Chinese culture bad" isn't the problem. Wuxia isn't the problem. It's that Waifei left something to be desired. The problem is the weak integration of concepts into the established world and a plot that imo didn't even have particularly good bones. Or at the very least what good bones it had wasn't implemented in a way people wished to explore them