I wonder if this is related to the low pay. I'm a part time working musician (as in, don't quit your day job). I've noticed that how the musicians are treated by both bandleaders and venues is roughly proportional to how much we're getting paid.

But I've also noticed that the abusive environment that we've heard about at the top of the business, doesn't necessarily trickle down to the lower echelons. At the level of work that I typically get called for, bandleaders who abuse their players get weeded out very quickly.