I think that an employer should be able to offer a job, not US residency. I think an investor should be able to offer money (and advice, guidance, support). But not a green card, no way.
Think of the implications here. A young investor really doesn't need the money. He's ramen profitable. But he needs the investor's permission to be a startup in the us! Well, that's one way for VC's to get the upper hand in an era when their money doesn't matter as much.
Look, I know hacker news folks tend toward the libertarian side and are generally skeptical of government. But I want the people who decide to award green cards to report to the voting public, not to Larry Ellison. I admire PG, but he doesn't answer to me as a member of the voting public, and he shouldn't. Once VCs gain control over the immigration system, they assume a government role, but we can't exactly vote them out of office if we don't like their decisions. And even if you have faith that PG will be a good guy, do you feel that way about "credible VCs and lawyers?"
Winston Churchill said "It has been said that democracy is the worst form of government except all the others that have been tried." Personally, I'm not all that interested in trying out a regime of VCs, no matter how credible a panel has found them to be.
As for the "Green cards to all CS majors" idea, I think a very narrow rule targeting CS would discourage US students from this field, and encourage them instead to pursue more protected degree paths like law. I'm worried about any policy that would drive the already low interest in CS among US students even lower. I also think a University should be in the business of granting degrees, not US residency.