There are some jobs (for example as referenced elsewhere hedge funds) where employees have knowledge that could be directly damaging to their former employer if it were taken to a competitor.

For example, other Fund X has a huge short position in a company. The way that finance solves this is by paying employees to stay unemployed (and not take their potentially damaging information elsewhere).

There isn't really anything directly "in it" for workers, so paying them out for their time seems reasonable.