This is a good point, but it does put them in a temporarily highly exploitable position. In some sense they are being paid later in their career for the work th

This is a good point, but it does put them in a temporarily highly exploitable position. In some sense they are being paid later in their career for the work they are doing now, and so have lots of incentive to put up with bad behavior. I see this as similar to "lottery ticket" fields like entertainment.