The threat of randomly being fired will cause many focused workers to change how they act. They stop trying to help each other, blame increases and internal politics dominates.
If this continues the remaining employees try to hire new employees with a fatal flaw so when the next wave comes they will be the first out.
I'm not saying that N% layoff is a necessarily a good practice. My main objection was to the notion that companies are created to take care of the employees. To me it's the role of the state to take care of the people, the companies are here to be efficient for eveyone's benefit.
If this continues the remaining employees try to hire new employees with a fatal flaw so when the next wave comes they will be the first out.