GM, most Chinese men aren't really that interested in hooking up with foreign women. They'll consider it the opportunity presents itself, if there is an attraction there, but it isn't generally something they go looking for.
Many (not all, or even most) Chinese women DO go looking for relationships with foreign men.
In China, as with most traditional cultures, it is acceptable for a woman to marry "up" but not so acceptable for a man to do so. Until fairly recently the huge discrepancies between local and expat salaries mean that the foreign partner is almost always the one who is "richer." Also, until recently, foreigners meant status. So a foreign partner was seen as a step up from a Chinese one.
Of course times are changing and blah blah blah but I think that's generally why Chinese women go after foreign men (with the conniving etc.) but Chinese men don't go after foreign women in the same way.