I agree with most of your comment. One thing to note though is the whole scandal where Steve Jobs colluded with other firms into a non-poaching kind of agreement, essentially distorting the market. So that is a possible outcome as well.
Far from that "hurting startups" it would be a benefit to all tech workers as wages would rise across the board.
This framing of "hurting startups" is a euphemism for "hurting investors" or "hurting the wealthy". It's roughly the same complaint as when they claim that there are "tech worker shortages".
They want to pay employees pennies on the dollar, full stop.