Western society -- and the USA in particular -- isn't generally receptive to the notion of an Asian leading man. That's why in those rare instances where an Asian fella is the leading man, he still maintains a distant and chaste relationship with the female lead. (The King and I, anyone?) Asian male actors usually get portrayed as either chaste action heroes (Jackie Chan), nerds (Hiro!), or (more recently, as on 24) shadowy agents of various Asian countries.
Then there's Jet Li in Unleashed. They hint around at him and the female lead (I'm forgetting her name) having feelings for each other, but nothing happens. Jet Li is considered to be one of the more physically attractive of the Asian leading men, but even he is treated like a eunuch. Ditto for Chow Yun Fat. And of course, neither one is regarded as a Hollywood heartthrob of any sort.