I left my last job because - in short - I was lied to.
The company had been around for a while, and I had worked there for two years. I really enjoyed being around my coworkers and management. All in all, it was a great development environment.
Then, rumors and confirmation came that the company was being sold. The new management came around, and everyone was promised that there wasn't going to be any drastic changes. I had my doubts, though, and voiced these to my teammates.
A day came where we were called in individually by the HR rep for the new company, to discuss our "re-hire". Now, my other teammates all got called in first. I found out from them that they had gotten raises. I thought - interesting; maybe this was going to work out. Still, I was wondering why I, and my supervisor, seemingly were last to be talked to...it soon became apparent.
They essentially told me that they wanted to keep me on, but only at a salary that was about 13% less than what I was making! In other words, they wanted me to stay for less pay.
Right.
I told them (well, you can imagine what I told them), and that they were fools to think they could hire anyone to replace me at that salary; I already knew I was undervalued, and I told them I could do better elsewhere. I packed my bags and left, but not before I let the rest of my team know what was up: I believed that the entire team was going to be canned, once they had completed the integration of our system with the new company's stuff.
I later found out my supervisor had basically gotten the same treatment as I did. We both quit, reducing the team from six people to four. Oh - and I guess I then knew how they got the raises. I'm pretty sure the new company had planned this to force us both out. I don't have proof, of course.
A couple of months went by, but I did get another position - this time making close to 25% more than my previous position. So - a two month "vacation" (needed, actually) - a large bump in salary - and a horizontal transition in my skillset (moved from LAMP to a javascript/nodejs stack). The company I work for now is small, but comfortable, and the team is top-notch.
My old teammates? Well - I thought they'd have at least to the end of the year; I told them as much when I left, but I warned them to polish their resumes in the meantime. Ultimately, though, the team was dissolved completely right after they finished the code transition, and only six months after I had left.
Just like I thought.
I'm sure had they kept their original promise of "no changes", everyone would have stayed and worked as hard on the product as we ever did, and enjoyed it. But apparently, they didn't really want a US-based (they were international) dev-team (they already had one overseas at their headquarters) - they just wanted our infrastructure (I worked in back-end cloud server management and automation development). I doubt that they ever really wanted a dev team in the sale to begin with.