CEOs should get a bonus because they fired people when it was necessary. Otherwise a CEO would make the easy choice and not fire anyone and you end up with a corporate culture like Japan, where people are rarely ever fired and there are hoards of people glued to a job doing unproductive work.

Firing people is a way to avoid a company's workforce from stagnating. It lets unproductive people in one environment find a new environment where they can meaningfully contribute. One should never avoid firing someone, instead what's important is ensuring that when someone gets fired that they aren't left destitute or desperate and that there's a path available to them to find new gainful employment.