There are exceptions but unfortunately these people don't generally know how, or are not willing, to do what it takes to move up into positions of authority. What usually happens is their managers will take credit for the work of the talented and then not know how to implement the ideas properly. This has been true throughout history and can be seen if you study the history of flight and who really invented the aeroplane, the history of Edison versus Tesla etc. In all these cases the ones that got credit were mostly good at self-promotion and aggrandizement. Such is the case with today's WDI management. I believe the abysmal quality we have been seeing in the last 15 years is mostly due to this.
We have always had examples of this issue but it has become rampant in the past decade or so. I've witnessed it personally and through the eyes of my best friend and business partner as well. Coming from him it is even more disturbing because he was hired at WDI, tutered and mentored by the guys that esentially invented this industry: Ward Kimball, John Hench, Marc Davis etc. While I worked with these guys, just as you have, I would venture to say very few were extensively trained directly by them as much as my business partner was. If you think I'm negative you should hear him talk. According to him just about every product that has been churned out by WDI for WDW in the last 15 years has epitomized an anti-Disney design philosophy. Once again there are a few exceptions that somehow made it through thankfully.
What is the solution to all of this? Executive leadership needs to recognize the problem, clean house and make a dramatic shift in design operations strategy and philosophy. The real problem is I don't see many in the executive leadership role that would be willing to do this. It needs to come from high up and they are too busy looking at their spreadsheets and expense accounts to care right now.
I hope the tide is turning as some claim. Unfortunately I don't see it yet.