There's a period in the lifecycle of a product, where things are a bit chaotic and the nature of the problem is not well understood. That's when engineers call the shots. Once you're past this point and things are a bit more stable, then you start seeing these politically savvy people jockeying for position. If management is not competent, then you start seeing these types advancing in the ranks and at the same time, talent starts leaving. This is a downward spiral that is very difficult to revert.

Engineering failures are very easy to spot and correct, but bad management takes longer to spot. Having the wrong people calling the shots is just one way management fails.

I guess the point I'm trying to make is that this erosion of status is actually a local phenomenon and a sign of dysfunction. Successful tech business will try to retain their talent with promotions, actual career tracks for engineers, etc.