I don't necessarily disagree with you but I think there is a second half to the problem. Half the managers are as you describer, but the other half are put in management positions on the basis of only technical ability and actually have no clue how to manage a team and in fact don't really care about doing that at all. Their passion is tech and will always be tech, but they are managing the team for status or career progression or whatever.
Yes, you're right, I think I described the one end of the spectrum where you have someone that chose to move into a management role because they never were that good at the hands on work, and on the other end of the spectrum, you have the brilliant genius hackers that think going into management will help them advance their career, not realizing that the skills that make them 10x engineers are not going to help them even be a 0.5x manager.
