Why do incompetent managers get promoted?

In my experience, incompetent managers often don't realize they are incompetent. They are confident and exhibit traits that do not harm others.

Competent mangers often are aware of their flaws and capability gaps. They work too much and are often overly critical of themselves and their projects.

How many times do people who are good at their jobs get promoted just because there isnt anywhere else to go? You cant make any more money at the level you are without switching companies so you get stuck going into management.

I got promoted to being a manager of a small group just because there wasn't anyone else to do it and I am completely incompetent as a manager of people. I don't enjoy it and didn't ask for it. It is only a source of my continued disappointment in my lack of competence. It does however pay better.

That sounds about right. Also it doesn't matter if they're incompetent so long as their bosses find some use for them. That is, if most of their employees think they suck, but their bosses and grandbosses are happy with them, then they get promoted.

I don’t agree with anything in this article. Incompetent managers get promoted because the things they are competent at are not the things their employees want them to be competent at. There is a dichotomy between traits that get people promoted at large companies and traits that make a good manager from the perspective of subordinates. Those traits only sometimes overlap. Thus the whole argument is predicated on a false definition of “incompetent”.

edit: people might ask, so here's a list of things that, in my experience, get people promoted at large companies:

politics, self-promotion, networking, choosing the right (high-visibility) things to work on, taking credit, delivering new revenue and/or new marketable shiny products/services, having the right senior leadership mentors/wing-people.

Note how none of these really require that a person be good at actually managing a team of people effectively.