People stick around in toxic environments mostly because of social reasons. Adversity breeds camaraderie. When you commiserate with people on a regular basis about the shitty work environment and terrible company policies, you build mutual trust tend to become really good friends with them. Leaving those people behind can be tough for a lot of people, especially if it is their first job out of college (and they don't know what they are missing out on).
This is a great point. I worked at such a company in a satellite office. A favorite activity was to get drunk and bitch about corporate, etc. Everyone loved each other, but _hated_ the company.
There's a right way and a wrong way to do this. The military make boot camp/basic training tough in part to build camaraderie amongst new recruits, the experience binds them to everyone who has been through the same ordeal. But that is in service of some higher ideal than "shareholder value".
It doesn't end after boot camp, though. We frequently referred to the Green Weenie, which was the omnipresent malevolent force that made everyone miserable. It's the main reason why I got the hell out.
I've found that a lot of other companies seem to have Green Weenies, and I do my damndest to avoid them. Five years of getting fucked was enough for me. At least buy me dinner first.