I don't have a macro-level answer for you but an interesting anecdote: we opened a job for a Software Designer and looked at the first 9 applicants. All of them were in need of H-1B sponsorship, most were Indian, and most were "software-engineers-turned-designers". So at a micro (company) level, we hire immigrants because those are the candidates we receive.
Note: One of my parents is an Indian immigrant. I have worked with many great Indian engineers and many not-so-great, just like every other nationality.
> One of my parents is an Indian immigrant. I have worked with many great Indian engineers and many not-so-great, just like every other nationality.
This kind of blatant, wholesale dismissal is part of the problem. It's not "just like every other nationality". It is overwhelmingly indian nationals abusing the system. Why would we spread the blame to nigerians, or hungarians for what is an indian issue?
Note: One of my parents is an Indian immigrant. I have worked with many great Indian engineers and many not-so-great, just like every other nationality.