Well, I guess it's a cultural thing, and you are probably right. Taiwanese are more ... reluctant about fully revealing themselves. And you mentioned planet Romeo, which is still a Date-match first, other fetishes second, site. People might be more conservative because they wish to keep their options opened. As you mentioned, if "always safe" does not always mean what it means, the status becomes moot. Yes, the society and laws have progressed towards gay rights, but the culture is still harsh against gay people, even the gay community in Taiwan itself sometimes could still be a little judgmental. This prevents some of the fetish activities taking place in Taiwan. It is like, "You want people to respect gays? Be a role-model gay first".
I guess I don't make much sense, sorry for my poor English.