Management is a service task, it does not produce value itself. Good management is important to prioritize, allocate resources and resolve conflicts. But that is not how MBAs seem themselves, they see themselves as the most important thing around, they're the ones in charge after all. And damn physics and reality, the spreadsheets say you can get get a baby out in a month if you use 9 women to do it. Soon management captures all the attention and sucks away all the money, and shortly thereafter end up with a moribund shell of the former company. You can tell how close to moribund a company is by looking at the manager to worker ratio. Get out of there once it climbs much above 1 to 10.
There are good managers around, but they're almost as rare as unicorns.