A lot of games simply don't work on PC, take SSX or Skate for example. You can't really emulate the two stick controls with a keyboard and mouse, but you can't guarantee that someone will have a controller.
you can't guarantee someone has a controller on xbox, it is assumed that they do. likewise, if your game says "best with a gamepad controller" on the front, it should be assumed they have a controller.
Explain to me how you would use an Xbox without an input device.
I enjoy them as long as they're defined to be on the console.Examples being ACE COMBAT and HAWX.