Also, the vast majority of people on H1-Bs that I've worked with are quite... average. It's nothing against them, but I doubt they were blowing people away in the interview. Many of them do have better attitudes, though.

That's not to say that there aren't exceptional examples, or a given candidate was bad, but we absolutely could of hired some kid from university, or a mid-senior level from a US company. They just tend to have more demands.

It's not exactly a secret the main reason for the program, is to lower wages here. ie. keep the wages of nationals in check. Of course, you also get access to a better deal on labor, and people that want the job very badly.

I could be off base, but many of the people I've worked with on H1-Bs simply cause less political problems. It's not necessarily a cultural thing, as I'm including many different countries. They have the threat of deportation hanging over their head.