We don't value good management. One reason is that we don't see it often. Which means we think it doesn't exist.
Another is the messages we are sent - Michael Scott, Dilbert, Office Space, etc. All entertaining and funny, but they make us think that all managers are either stupid or evil (or both).
Also, we don't promote the skills that make a great manager. We seem to think manager is something anyone can do - but we get proven wrong time and time again. This is our own fault, most businesses haven't changed the way they select managers in decades. Which means we look at high performers in the current role, not who has the potential to be a high performer in the manager role.
Here is a test I like - ask a manager what they do. If they put the importance on the function (like IT, Marketing, etc.), it is a good bet they don't get it. If they put the emphasis on the managing, in all likelihood they understand the importance of people.
Great companies value great managers. Great managers have successful teams. Successful teams make great companies.