This goes along the lines of the saying,
The pace of the leader determines the speed of the pack.
It often blows my mind that managers think they can manage just the processes, without needing intimate knowledge of the customers, the products and especially the technologies behind them. This “on the job ignorance” is a clear and present danger to a business. In most cases, it only means the team becomes a bit less professional, until this “managing moron” leaves. In the worst case, it means fatal errors will be made and at huge costs and if the company isn’t careful, it means complete and irreparable failure.