I don't follow. You are right, but....?
As a general rule, I find that third-person (and sidescrolling) is better suited to a controller, while first-person (and top down / isometric) is much more suited to a mouse & keyboard. So action-adventure games, fighting games, platformers, and racing games tend to be better suited to a controller... while first-person shooters, RPGs, strategy games, and point & click adventure games tend to be better suited to a mouse & keyboard.
It's a fairly reasonable assumption that a lot (not all) of the people who say third-person is so much better are playing with a controller.
