Inferno is for the hardcore that enjoy banging their head up against walls. I'm currently stuck farming in Act 1 as it sounds like you are as well. Not gonna lie, it is getting a bit boring but I knew that is what I was getting before I even started. You conveniently left out raiding in your WoW comparisons. Raiding in WoW is like Inferno in Diablo. Not a lot of people are going to do it due to the shear time requirements and difficulty. They added it specifically because Diablo 2 was a joke. Fun yes, but extraordinarily easy. And we complained about it. If you enjoy Diablo 2 then as you stated you can run up thru Hell difficulty. While the drops are lower, you do have a chance for level 61 & 62 gear to drop.
Of course Diablo 3 is not hard either just tedious.