When 90% of the game is a one-handed click-fest it's kind of blah to suddenly need a hand on the keyboard in the right spot.
Like I said though, it could be rooted in me thinking a gamepad works best for these types of games.
Both Diablo 2 and Diablo 3 are not one-handed clickfests, even though the former can be played as such.
Diablo 3 differs from D2 in the sense that it forces the player to use both hands already early on in the game. Also, I feel like I am using the left button a lot less than I was in D2 - you simply don't need to click as much. Your left hand is a lot more involved.
Furthermore, you can assign any skill - including the basic attack - to any button. So if you want to play it in a more 'consoly' way then you can put your primary attack on, say, 1 (though you will still have the aforementioned left-click 'issue').