Because the space game that he's making, and Scrolls, are REALLY advancing the industry compared to what EA are doing. At least EA are making games people want to buy; Notch is just making games he wants to make.
(The appeal of the space game is programming a simulated CPU. That's fun to a vanishingly small percentage of potential buyers. And Scrolls will have never-ending paid DLC.)
The word "indie" is just an excuse for making games with weird gimmicks. We shouldn't be buying games to support indie game makers, we should be buying them because they are good games. You don't get a free pass on quality just because you're not contracted.











