For not wanting to put up with a CEO who is quite publicly a douche--and worse--giving them ultimatums like this instead of just laying people off forthrightly?

For not wanting to put up with a CEO who is quite publicly a douche--and worse--giving them ultimatums like this instead of just laying people off forthrightly? Musk is well-documented as a person who is terrible to work for, and in general, very few people want to work under the kind of regime he is trying to institute at Twitter. The fact that a number of Twitter employees feel free to quit is merely a matter of market economics.