Because your boss isn’t as competent as you are

Your boss once did the same work as you.

You assume that he must have been good at it.

You assume that he must have been promoted because he was good at it.

Often, he tells you to do something that’s obviously wrong.

If you try to correct him, he’s furious, and tells you to do as you’re told.

Occasionally, he tells you to do something that would be disastrous.

You’re left with the choice between infuriating him and working knowingly towards disaster.

Every time you meet with your boss, you find yourself trying not to touch on important issues, on which he might say something that would commit you to such a disastrous course.

You come to realize that your boss was never any good at the work you do.

He must have been promoted precisely because he was no good at it.