This is why I left my last employer, and they acted absolutely shocked when I referenced it in my exit interview.
My manager was absolutely obsessed with KPIs and would every month review our team's numbers. My numbers were always exceptional, and in terms of overall team rankings I was almost always number 1. Regardless, she would find the one metric in which I fell below average (usually only one KPI was below average while the remaining 15 or so KPIs were above average) and tell me that I had to get my act together "if I wanted to keep my job".
I once decided respond to and challenge this threat, and she just lectured me about working in an at-will state, and even had the nerve to wink at me before asking me to leave her office. The quote I took away from her reply that day was "you have nothing to worry about as long as you do your job well".
It was after this meeting that I began aggressively putting out my resume and applying for jobs. I found a better job with higher pay and better benefits in less than a month.
A week after putting in my 2-week notice I had an exit interview in which they asked me why I started looking for new jobs, and why I had never talked to them about my lack of satisfaction working there. They told me it was "very odd" for someone to leave without warning, and said that they regretted that there was never a conversation in which they could have "retained my talent".
I told them that being threatened by my manager with termination every month and never once being praised for my high performance had motivated me to find a job that offered better job satisfaction and security. You would have thought I kicked a puppy from the reaction I got from the leaders. My manager immediately started with a "I NEVER threatened to fire you!". The CEO just shook his head. He didn't say much, but I do remember being told "this is a risk you take in the working world" like I was upset about the possibility of being fired rather than the regular verbal threats of it.
I countered by explaining that "if you want to keep your job" includes an implicit threat of termination, and that hearing this threat when your numbers are above average is demoralizing and makes it feel impossible to do a satisfactory job in the eyes of management. My manager responded with "I say those things hoping that it will motivate you and the rest of your team into doing a better job! I've always been on your side!".
My response was simple: "You did motivate me... To GET a better job. I was already doing a great job, this place just didn't recognize it". That was the end of the exit interview.
Two days later, they were begging me to stay for another MONTH because "nobody knows how to do your job". I suppose they should have thought about that before they made my employment a bargaining chip...