I know that this is anecdotal and not necessarily representative of anything, but, I hear people use kowtow in all sorts of context, and certainly not limited to references to China or other Asian nations/ethnicities.

In fact, it's been so universal I never even made the connection or wondered about the etymology. Finding out that it's a loan word from Cantonese is something I learned due to this thread.

All your examples are false equivalences. The word "kowtow" is a perfect description of a relatively complicated ritual that didn't already have an English word for it (you could maybe substitute "placate" or "show deference" but these can have other meanings in different contexts). Words from other languages like "karaoke", "restaurant" and "prima donna" have always been incorporated into English when no specific substitute works well enough (of course this isn't specific to English, but it is a very English habit).

Your Mexican example would be using (I assume?) the Spanish of whatever word would work just as well in English, and I've personally used and seen people use words like "bruh" and "yo" with lots of different people. In fact, where I'm from "bruh" is a very typical "white" thing to say.

All your of your comment is intentionally stripping things of context in a pathetic attempt disarm a fair argument without addressing the actual substance of it.

Saying “kowtow”, “bruh”, “what’s good”. Not a problem.

Someone who never says “bruh” or “what’s good” suddenly talking like they’re extras in a Migos music video to their black coworker is not cool.

Saying kowtow, but only in reference to Asians and always using “appease” in other contexts, is not cool.

Yeah I know HN is mostly white guys who squirm at the idea of race and think “I don’t see color” is an ok thing to say, but if you’re not going to at least try and take someone's arguments for full value, even if you don’t agree, don’t even respond, it’s insulting otherwise.

I don't have an issue with the base argument, I agree with it. I'm saying the examples are false equivalences because in the context of the original comment, they are. There's nothing in the original comment that indicates the use of the word "only in reference to Asians" because you have a sample size of 1 (again, I've personally heard it used in non-Asian contexts too). Making an assumption about the intent of someone's comment doesn't fit my definition of a "valuable argument" outside of more context, but as I said I agree with the general issue with individuals using certain words only in certain racial contexts.

Point out which part of my comment is saying I’m talking about a single comment and not a general trend in the US.

This kind of useless deflection is insulting to basic intelligence.

I'm not sure if you've picked up the main point of what I'm saying or are just performing some deflection of your own, but it stands nevertheless: you've got a reasonable argument that I get behind, just make your argument without using misleading examples.

Not sure why others seem to disagree, but kow-tow indeed conjures up fu manchu-esque images, a sort of comical or repugnant representation of groveling associated exclusively with Asian culture. Exactly as you say, it's not necessarily racist in intention of using the term as subservience, but racial nonetheless. Separately, the actual kau-tau seems to have meant something specific as a ritual of respect. Used here, its generalization to mean forced groveling or appeasement is strange, as it implies the person or entity doing it is a loser.