WHY are there managers who are willing to compromise their moral and professional integrity simply to avoid contradicting a despotic CEO?

The CEO tells him to go and see an employee, shout at them and tell them  that either they do as he says or he’ll sack them. And he goes and does it, knowing that neither the content nor the manner is right. There are people who lack decency and moral integrity.

Fear of being sacked? I’d rather be sacked than treat others badly just because the CEO asks me to.