This just isn't true, for a lot of reasons.
To start with the obvious, most cultures have some conception of the great power that lies within the unarmed warrior. Just look around you. Whether it's "Hollywood action flicks" (that long pre-date the current spate of movies) with people being able to punch their way out of any problems, or the real-life glorification of Krav Maga and Afro-Brazilian Martial arts, or the Vedas describing the legendary fights and their heroes (which led to codification into actual schools of fighting systems) .... or even the current hot trope of superheroes, where, as we all know, Batman doesn't use a gun.
So to say that the idea that unarmed combat is only something that only belongs in some kind of wuxia fantasy just doesn't make sense.
More importantly, you are discounting the fact that D&D has always been a melange of different influences. This argument is simply a rehashed version of the old, "I don't want X in MY D&D so no one else should have it either." Just replace X with anything- science fiction? Anachronisms? Gun powder? Just look at the original class listing of D&D, and what is was truly inspired by-
Druids are the Roman recounting of Celts. So we're looking at sources from the 150 BCE to 100 CE.
Assassins, despite the trappings, are derived from the Middle Eastern Hashshashiyin, as recounted to the West in 1300 by Marco Polo.
Thieves were brought to Gygax as "box-men," with abilities that didn't exist until much later and are, again, based on romanticized reports from the Middle East first reported in the West in 1800s.
Bards were stated to be an amalgamation of Norse skalds, Celtic (?!?) bards, and southern European court minstrels.
Clerics were an admixture of vampire hunters from Hammer Horror films (1960s) and Odo of Bayeux (1097)/
Paladins were based off of Holger Carlsen from a book.
Rangers were ... well, we all know that one.
I could keep going, but it should be apparent. Ideas came from everywhere. They were put into a blender called D&D.
Now, all that being said, the original Monk was based off of Remo Williams in the Destroyer series of novels, as well as an influx of content produced in Asia (at this time, mainly Hong Kong). This was during a time when there were two separate things going on- first, appropriation. Remo Williams definitely trafficked in some of the uncomfortable tropes that were prevalent back then. White guy travels to "orient" (usually made up or unspecified or legendary location), finds old master, trains to become the greatest ever. Then again, we still see that today- Batman Begins, anyone?
More importantly, however, this isn't the 70s. Asia (generically, but more specifically the cultural powerhouses of Japan, South Korea, and China) export a lot of their culture to the United States. Heck, RRR just won an Oscar- showing that Bollywood is also getting its due, finally. This is a good thing! People today are able to enjoy amazing culture from all over the world, easily, and we see it reflected every day.
To stand athwart this type of progress and say that you don't want it in your D&D is fine, for your group. But I will not deny others the ability to play what they want.
Now, I do think that there are interesting questions. Asians Represent want the Monk to swerve harder into a more "Asian" approach- what is that, pan-Asian? Fantasy Asian? Personally, I think that the idea of having a more universalist approach that also allows people to create martial artists with the fantasy flair that they want is a better approach; whether it's a "Kung Fu," or "Capoeira," whether it's inspired by the Seven Deadly Venoms or Avatar: The Last Airbender or Roadhouse or RRR or whatever they want.
