My guess is that they really do enjoy the other parts of their job and even the company itself, and are really sad about the bad parts that are making life difficult. That coupled with a hope that things might get better.. Everyone has a different breaking point when it comes to these things.

Maybe you just want to stick it out until the first year cliff when it comes to your RSUs so at least you have something to show for the below-market salary you agreed to. It sucks that you have to suffer through this crap but sometimes the potential financial upside you might be able to hold onto is worth a little more pain.