Knowledge is power. Ignorance gives birth to futility and frustration. A guy with no knowledge of acoustics or measurement capability sending GIK (or their competitors) 3K and say. "Tell me where to put it" is pretty much like a blind man in a dark room with a shotgun. If he shoots 6 rounds, he is probably going to hit something, but it is a rather inefficient approach. These audio consultants can certainly help, but I have had enough experience with them to know their recommendations are based on what they have found to be generally true. I've gotten bad advice from more than one of them.I think you are totally right...
It really depends upon what you want. If you don't have time, do have, money, and want to make your room better, GIK and others can help. If you want to transform your room/system into the best possible listening experience, you better be ready to do the work it takes to fully understand the principles and learn how to use measurement tools to put those principles into practice within the context of your room.
It takes me 2 years.... It is not perfect, but it is so good that before and after had no comparison at all.... It is like upgrading from the worst system to a very good one.... Not the best but for panuts costs and fun experiments... What can i say?
My best to you...