Even if we agree with all the stereotypes being thrwn about, I dont see a problem.
guys who dont want to marry girls in US, they are not in the available candidate pool anyway. If we take your statement that these guys want submissive traditional etc etc from Pakistan, then well, let them, those are not the guys you will go for anyways. so the girls in Pakistan.. its not their fault to say yes to these guys. if the guys want girls from there, and those girls like the guys, then whatever each sides reason may be, their choices are their choices.