Coding isn't just about writing amazingly optimized code, or running as close to the metal as you can get; or heck, it isn't even about not crashing. The whole reason for Java and the other high level languages is so that less analytical geniuses and more artists/thinkers can get into programing.
Notch is a perfect example of a regular guy, who isn't really the greatest coder or artist, but never-the-less, still managed to outdo every single 100+ team dev house. Why? 1. the balls to buck absolutely every convention. 2. the presence of high level abstracted languages and libraries for him to build on. 3. the willingness to borrow from what comes before (Infiniminer, Dwarf Fortress, Gary's Mod) 4. pure damn luck.
Notch is a phenomenon, not simply because minecraft is an amazing game, but because we love a rags-to-riches storyline :)