Sometimes it is a matter of what you are exposed to. May not be the case with you, but maybe they are what you have been exposed to so you take them into consideration more. Don't give up if that is what you like, but keep your eyes open for other opportunities.
Maybe because they think Asian guys are more handsome and brave.
Ever heard of Bruce Lee?
Some of them do. I can't think of a reason a white girl would not like an oriental guy.