I can only speak personally on termination of employment. When dealing with a low performance h1b employee, they were treated exactly like a regular employee and were given a low performance review. The company did stack ranked based year cuts so he knew he that he had a high change of getting cut with a below expectation performance review and a PIP and had 3 months to look for a job. Firing h1bs out of blue would make it hard to hire other h1bs. There maybe companies that abuse the situation, i have yet to see it. Most people aren't sociopaths and have empathy. Being a terrible leader/person makes it hard to do startups since talent won't follow you.
