Inferno mode is stupid. There's no incentive to play in groups for one and the difficulty of it wasn't very thoroughly thought through. All they did was pump damage and life numbers of monsters to an arbitrarily high number. This makes the game difficult not in the sense that it requires skill, but requires gear. Inferno is just one big gear check; and the gear needed to progress won't be found from drops but from the AH, but the D3 economy is so ridiculously inflated anyway.