You're reading the wrong words in that, and not counting the fact that there's already Nagas, Rocs, Oni (5e dropped Ogre Mage for good) already in the core D&D books. And I don't think there's anything wrong if a traveller from Asia teams up with an Arab and Carribean guy despite being of species loosely based on European folklore end up traveling the world beating up creatures from Europe, South America, Africa and Asia.
What I am taking exception to is that you are saying that we can't have all the fairy folk that people of Japan, Korea, China, Mongolia, Thailand, Vietnam, Laos, Nepal, Indonesia, India, etc. said lived in their forests and mountains and rivers. Or-- as many of them as can fit because these are an awful lot of countries we are trying to cram in here and there are probably just way too many potential player races.
Instead, we got to erase all that and impose Tolkien because Tolkien is "core". Even though Tolkien's races were Tolkien's races primarily because he was basing his setting on Britain and the assumption there was Britain.
And it is perfectly understandable that, in a Eurocentric setting, that the fairies and goblins be the non-human PC races of that setting. But it doesn't make sense when you are trying to use another culture as your primary core assumptions, that it should be
that culture's fairies and goblins that are the non-human PC races. Insisting that, instead, the setting only have Britain's fairies and goblins utterly undermines the entire point of even having a different setting. And no amount of tweaking is going to disguise or hide or fix that.
Obviously I am being over-the-top and a bit sarcastic, but your attitude really highlights why, perhaps, it would be best just not to have an Asian-inspired D&D setting at all-- because the regular D&D players are unwilling to accept any real change to their Eurocentric assumptions and insist on imposing those as the default rather than allowing for an entirely different set of norms.
That isn't do say that you can't have a couple Dwarfs and Elves who wandered in from way out in that mystical and barbaric west appear within the setting. But the core in such a setting should be that you are going to play a Kappa, not a Dwarf. You are going to play a Dokkaebi, not a Gnome. You are going to play a Naga, not an Elf.
Plus... you know... why pass up the excuse to create a dozen new PC races, most of which are in no way based on something that was originally created as a monster the PCs battled and killed and was never given much thought beyond that, and instead you just have a few folklore stories and your own imagination?