I think we might be seeing a bit of 80/20 rule playing here...as the old saying goes, the first 80% of the project takes 20% of the time, and the remaining 20% is the most arduous.
If I had piles of cash in the bank, I might be less inclined to see something through once I hit that 20%...from what I hear this seems to be how Notch writes code in general, and now that he is very wealthy...well....
That makes a lot of sense. Once you get to a certain point where the core of the functionality is built and the rest seems easy and/or tedious, it might be tempting to hand that part off to someone more interested/with more time/etc. wouldn't it?
If I had piles of cash in the bank, I might be less inclined to see something through once I hit that 20%...from what I hear this seems to be how Notch writes code in general, and now that he is very wealthy...well....