People too. There's plenty of people that would like to move to find employment, but have a mortgage that they need to get out of first. The market is pretty terrible at the moment, and these people end up being stuck. I know a few personally.
America has too many poor people, and not enough rich people.
And it's easier (and more legal) to import rich people than to kick the poor people out.
It makes sense that the countries of the world should be competing for the most talented people. And being rich is the best proxy for being talented that we have.
