Then they should compensate commensurate. As it is, I suspect that many are a market for lemons. Primarily the "seniors" who would take these jobs are the ones that can't get hired at 2x - 3x the comp, or (I suspect much more commonly) think they can't. I'm going to do my part to try and make sure more engineers know that they have options beyond working for shitty startups that dangle worthless equity in front of them.

This. You can be average or mediocre at a big company as there are lots of places to hide. There is nowhere to hide at a startup, in addition, a single hire can make or break a startup. More then anything a startup is just a collection of talent. Unlike a big company which might have physical assets, IP and other valuables. A startup is really just a pool of talent. So if there isn't any, well it wasn't going to work.