I have seen seen managers yell at employees who disagree with them. They berate employees for no reason. The level of narcissism among the senior leaders it is impossible for many to admit they are wrong or refuse to listen to advice or opinions from direct reports with years of experience. I am sure if a consultant gave the same advice they would accept it! In 15 years I have seen too many great managers leave (mostly those from other companies with much experience) because the bad managers (mostly long term 3Mers) feel threatened by them and make it a miserable place to work.
@5nvr+1lH6PevH hits the nail on the head.