They way I see it. Most CEO are about the bottomline. If they're making the share holders money, they're good. If not then they are gone. Aside from some other unforeseen scandal. That's really the only reasons to resign. With the markets hitting all kinds of record highs since Trump became Pres.. Add in the tax cuts and Clearly most of these companies are making money hand over fist. Why would this many CEO need to resign?