RE: national quotas -- it seems a bit weird that an engineer applying to Facebook would be told she can't get a job there because Disney hired too many people from her home country. Not that there aren't pockets of such weirdness baked into the current system, but this in particular is a negative consequence of what you're proposing.

I say this to reply to the first 3 paragraphs. I object to the last two paragraphs on moral grounds but have no desire to continue a conversation about them.