alt Hacker News-85,000 NEW visas granted each year, not including renewals - The mass majority of those are going into the tech/software - there are only around ~100k CS graduates each year - H1B workers will take much lower salaries and benefits than their US citizen counterparts.
And H-1Bs are easier to overwork and abuse because the threat of deportation and the dangling carrot of citizenship are very powerful motivators that don't exist with US citizens.