I think the trend is decreasing, because middle class/ upper class Pakistani guys do not want to live abroad. I mean why would they when they have generally a better living standard (drivers, high social standing etc), so they seem to be reluctant to move to places like the UK. I mean I know a couple of girls who have married well and have settled now in Pakistan maybe it is a reverse trend.
There will always be bad apples especially people (including men and women) who want to come abroad. I have seen people i know go through hell when their husband/ wife leaves and claims a lot of money in the divorce. They generally tend to win because the are the dependentones in the beginning.
I know some desi guys in the uk are blah, but a lot of them are nice.