They offer the kind of money they do because they have to and they can..simple.
Like everything else in life, it's a case of pro's vs con's. Some will take money over working conditions, others will take working conditions over $$$. Having spent the better part of a decade living in Asia and more recently, flying into SE Asia, it's simply not as easy to live there as it is US or Europe.
The biggest problem with becoming an expat pilot isn't finding work overseas and leaving........it's the coming back part.