Today we live in a fast paced, highly mobile world.
The old networks of family and friends that used to help people meet their mates is not nearly as strong as it was at one time.
Now he is at an age where he realizes that he is not going to be young forever and he wants to meet a younger woman, so he can start a family. The brides tend to be younger and more beautiful than the groom would be able to marry in the United States or Europe.
The grooms tend to be more financially successful and significantly older – often fifteen or twenty years older – than the woman would probably marry in her home country.
That is enough about scientific evidence, academic arguments, and media bias.