[singron]

The H1B makes it more difficult to change jobs or negotiate salary. Any interruption to employment is a huge risk to staying in the country. Thus those employees are more likely to accept lower offers and stay in those jobs longer.

E.g. a citizen can decline an offer in order to negotiate it up, but if the clock is ticking on your h1b, then you wouldn't want to get called on that bluff.

The limitations don't seem to dissuade H1b applicants, so companies like that they have more control over those employees without decreasing total supply.