Interesting thread. I reckon that many who dislike the game will tend to lack any creative spirit. Personally, the main appeal of the game has to do with creating and building. I see it as a 3D giant pixel world.
Also, it seems many people don't like the retro look of the game. Don't know about anyone else, but when I first played Minecraft, it did look and feel very retro. However, once you get higher texture packs, the game transforms. It doesn't take long to get into the game, then retro feeling disappears entirely.