They should pay unemployment insurance, because they contribute to unemployment. They should not pay social security, since they can't collect it. Whether Americans can collect is TBD longer-term, but we'll assume for now. Regardless, there are too many H1-B's. The companies that rely on them heavily are sellouts.
Sellouts? What exactly have they sold out? Do you think that they went into business to provide YOU with a job? Do they owe you a job? Is it your RIGHT to demand a job with them?
Or, are you overpricing your skills and hoping for a government intervention to insulate you from having to compete? That is the kind of protectionism that destroys US industry. That is the kind of crap that communist labor unions advocate. It is the LAST thing we need in the tech industry.
Frankly, any company that didn't hire the best people for the lowest wage would be the sellouts. Well, at least that's the way people who believe in liberty, the free market and individual rights see it.