Because Asian people are not creating them would be my best guess

I am of 100% Japanese descent (though yonsei - fourth generation American), and I would tend to agree.

Though perhaps it's not so much the character as the figure. With the Vicky base, you cannot make a truly realistic Asian. It's not really DAZ's fault. Using morphs to turn a Nordic-looking mesh like Vicky into an Asian just doesn't work. Oh, you can get a fairly good result if you want the "mannequin" look, but the other head morphs no longer work correctly. I love some of the "International Beauties" morphs, but they don't work with the expression morphs. The face gets weird lumps in it, the teeth show through the cheeks, and the "blink" morphs look hideous. Basically, to do it right, you'd have to create all new morphs for the Asian head. (Which is what e-Frontier did with Miki and Koji.)

DAZ could do "ethnic packs" that include all new head morphs to go with an ethnic morph. IMO, their INJ/REM system is perfect for this. Obviously, having separate head morphs for every ethnicity would result in a huge CR2. But you wouldn't need them all loaded at once, and with the INJ/REM, you could easily load just the ones that go together.

The Japanese Poser users do make Asian-looking figures, but they tend to be highly stylized/idealized - sort of anime-looking. Miki and Koji are the only realistic Asian figures I know of.

Skin textures...there's a lot of variation in Asian skin tone. Very dark skin is not unusual for, say, Japanese who have settled in Hawaii where it's sunny and everyone wants a tan. In Japan, fair skin is still the ideal (plus there's a lot less sun). I would like some paler skin textures for Miki; the existing ones tend to be either dark, or not Asian at all.

I would also like some nice natural textures. Most of the ones I've seen have a ton of makeup. There's a tendency in Poserdom to have textures that look very "made up" - the kind of make up most women save for evening, when they won't be seen in bright light - or very "realistic." Pores, moles, blotches, etc. visible from 20 feet. I generally like something in between. Most women wear at least subtle make up when they are out in public - enough to cover any blatant blemishes. Besides, makeup tends to look very dated, since styles in makeup change so much. I want pretty but not necessarily contemporary.