Bad ideas get stamped out by people pointing out they are bad ideas. If a CEO supports a spectacularly bad idea, it is not a problem if someone gives him the boot.
Even if the idea is completely unrelated to the company? And even then, we weren't talking about CEOs. We were talking about people like the low-level employees at GrubHub told that they should keep real quiet about their unapproved opinions if they wanted to keep their jobs.