Don't kid yourself, it is taboo in virtually every society, western, asian, arabic.... The few exceptions where a third sex is sort of recognized are few and far between. And the "Ladyboy" phenomenon in Thailand does not mean that "cross dressing" is not taboo. They are not "cross dressers."
As for why it is taboo. I think it is basically that the male role is being challenged. Society doesn't like that.
