And you would be right. The game itself is rather monotonous and is a massive grind with only small improvements over D2. Where the real effort was put in this game was the RMAH and how far blizzard could reach their hand into your pocketbook.
Inferno was not made extremely hard to complete cause players wanted it. It was made difficult to push you into the RMAH and spend more to complete the game.
Call it, "pay 2 complete" instead of pay to win but there so close does it really matter. To bad gamers forgot we hate pay to win (complete) type games at the possibility of a little cash in our pockets.