There's more nuance here. There're ways to "port" your H1B to another company (incl. while working part-time with one leg at a non-profit and another at a startup), but few want to go that route because of all the other bullshit we already had to go through.

I don't think we are in disagreement here. My main point is that many feel "pressure" from their employer. Knowing and keeping your options open and ready to act on them, even at other universities, empower all workers.