Government control of immigration is a natural consequence of government establishing and defending a border. If you want to take the free market to its logical conclusion, we should get rid of that too, and leave Silicon Valley to its own devices vis-à-vis fending off hostile foreign actors. Historically that sort of thing has not worked out well.
Note that the products/services made by these immigrants are sold globally, not just in the US. Google, for example, acquires more than 50% of it's revenues from outside the US.
If you don't object to google's selling it's services across the world on free-market principles, it'll take a rather large leap of (il)logic to constrain the employment to be restricted to the physical location of the HQ of this global company.
Movement of residents is fundamentally different than movement of goods. Moreover, nothing constrains Google from hiring people in locations outside the US to service those markets.
