Because Minecraft is a very buggy, poorly designed product. Notch is only "respected" as a programmer by people who have never looked into his programming.
Well it's good enough to make him a very rich man. Oh and when did you get a chance to look at his code and designs?
So because someone is rich that makes them a good programmer? I have done some projects with the Minecraft SMP protocol (which is awful), and I write plugins for it. So yeah, I know a bit about its design.
"Not everything worth doing, is worth doing well" -- _Soul_of_a_new_machine_