I love how Carmack is constantly pushing the industry forward.
He made raycasting engines when everyone else was still doing 2D stuff. He made fully 3D games when everyone else was still using raycasting. He built a game engine with completely dynamic lighting, when everyone else was still relying on lightmaps and some cheap hacks.
Arguably Duke Nukem 3D looked better than Quake, but polygonal was the future. Half-Life 2 looked better than Doom 3, but dynamic lighting was the future.
While everyone else keeps iterating current technology (often to astonishing results), Carmack does something new - something that may have a lot of drawbacks initially, but will be the future. I see the same happening in other industries - take Tesla vs. any other automobile industry out there for an example.
I haven't been this excited about a new piece of gaming hardware since I got the N64 for my birthday back in 1996. I'll buy it!
(Of course it's not only Carmack who is doing research in that department. This post isn't so much about praising him, as to praise innovative thinking.)