Earlier quoted context omitted.
Absolutely true. I saw this play out in my lab where we had 1-2 PhD students (including myself) and about 12-16 rotating postdocs. They worked insane hours for very little pay, no benefits, and produced 95% of the output of the lab. Our professor was definitely the "wrong" kind of professor, as about 50% of them left academia entirely and not by choice after being wrung dry of all productive output and then discarded…
> The professor also only hired visa applicants to have extra leverage over them. For any postdoc that thinks the university has leverage for this reason, if you are able to get a H1B, you can switch employers easily. You are not stuck at whichever company sponsored you.
* My understanding is that universities prefer J-1 visas in almost all cases [1][2], and such visas are not portable.
* H-1B is more flexible than J-1, but still not as flexible compared to a green card. In particular, the new employer has to fill out a new application, pay the fees, etc. Also, universities are exempt from the H-1B cap, but other employers may not be.
[1] https://internationaloffice.berkeley.edu/ucb_departments/h-1...
[2] https://postdocs.stanford.edu/postdoc-admins/how-quick-links...