Immigration is a privilege, no more unfair than all of capitalism. If a country decides things are x or y levels hard to immigrate thats great.

The problem is the moving of goal posts. For decades, h1b (which is an immigrant visa) was a stable path to immigrate to America. People see that, and there was an implicit promise made there. If the US wants to decide not to continue with this practice that is fully fair. Just make up the rules clearly and give people a heads up. Is that too much to ask?