Sorry to say, but its true, many managers purposely try to make the status quo more complicated than it is, or, don't understand that no matter how complicated their business is, it always helps to simplify it.
Taking a complex flow, like a supply chain, or various processes, or various internal business flows, is indeed complex, and often times difficult to improve.
But complexity itself is a barrier to improvement. People don't grasp complexity very well. You need to establish a common language, a way of looking at the issues and breaking down the complexity into manageable pieces.
Companies and managers who don't do this, or refuse to think it is possible to do this, end up improving nothing.