I would just like to point out that it can also have a negative affect on job liquidity. For instance why would I move, at expense to myself, for a job if there is a reasonable chance of being fired for something unrelated to my work and with little recourse. It also means I'm less likely to disagree with the boss because something going bad for the company is not as bad as me getting fired from my point of view.

Fair enough to say 'that these show bigger issues with the company and you'd be better off elsewhere' but it doesn't stop companies like these existing and minimising the cost to them isn't something I particularly support.