(e: This was in reply to Akalabeth.)
OK, let me summarise My Personal Views On Minecraft for the nth time:
There's a nucleus of stuff in Minecraft which is absolute gold, somewhere in the intersection of the construction and resource gathering and exploration mechanics which were laid down in infdev and alpha. My memories of late alpha and early beta multiplayer are rich with heady nostalgia. However, the actual piece of software called 'Minecraft' which contained that experience was incredibly incomplete, riddled with bugs and broken systems. Anyone who played back in those days surely remembers the frustration of waking up one day to discover that a routine patch had totally buggered the game. You couldn't really call it 'great', but it was dripping with promise.
But it didn't deliver. Mojang patched up the bugs, eventually, but as far as that core brilliance goes there wasn't much improvement or refinement at all, just some fairly inconsequential novelties. When Notch finally did try to really push the game's basic vision, the result was the Adventure Update, which mostly served to cloud the things that made Minecraft great with ill-fitting RPG fluff.
Notch caught lightning in a bottle, basically, and while that might deserve praise it was down to luck as much as his own skill. The real test of his abilities was whether he'd have the perceptiveness and creativity to take that idea to new and greater heights, and in that respect he, and his successors at Mojang, have failed dismally.