Yes, I have heard of brain drain. And people here are arguing in favour of brain drain rather than hiring citizens or paying citizens better, because they say that US needs these foreign workers. That's why I ask how it comes that their own countries do not need them?

Why should anybody be sympathetic to the so called "needs" of US companies hiring immigrants, but not be sympathetic to the needs of their home countries?

Sympathy for companies is usually conditioned on the fact that they give jobs to locals, or at least to citizens. If they're not doing that, then who gives a fuck if they aren't able to expand or profit at a rate that shareholders prefer?

But there is a class of people - most hackers included - who have had such comfortable lives that they aren't capable to even pretend anymore to sympathize with the producing class.