why? because there was an ultimatum? I don't really see it as bad management. Sometimes it doesn't work out, and that's fine. Sometimes a relationship that worked last year or last month doesn't work anymore... and while that's sad, it's also natural and should be okay. And sometimes, it's clear that the employee and the employer are moving in different directions. This is okay.
I think that employees need to stop thinking that getting fired is the end of the world, because it puts them at a serious disadvantage.
That's the thing; the negotiation doesn't end when you are done negotiating salary; and work is almost a constant negotiation. If you aren't willing to walk, or if you aren't willing to let the other guy walk, you are going to get screwed. Relationships end; it happens, be prepared for that eventuality financially and emotionally, and learn to move on.