Very good points.
I notice you don't mention Willits in your pantheon of id talents. Wisely, I'd say. His design stewardship of Rage -- and its resulting perfect banality -- was as much a lodestone around its neck as was one more advanced yet performance-lacking Carmack technology. Put together, the mixture was lethal.
There was an id fantasy game in the works, briefly, a decade or more ago; it was killed off in favor of another FPS retread. I wonder what might have been if a) the faction that wanted to keep cloning Doom and Quake hadn't won or, alternatively b) instead of id consistently shedding its most notable design talents leaving Carmack surrounded with people content to recycle the past, he had struck out on his own with a new group of talent and created something original.