[zdragnar]

I've seen execs come and go at several companies.

Usually, one is gently but firmly pushed out. The charade of them resigning helps them save face in a job where reputation is important. They are also less likely to speak ill of the company afterwards (especially if a severance of some sort requires silence).

Actually outright firing is more rare, since the company loses any leverage over their behavior afterwards. I've seen it happen, but only once.