Nothing is more frustrating than being unable to set the controls of your newly bought game to your liking. I tried out Dead Space two weeks ago. The first thing I always do in a 3D game is rebinding all my actions to the numpad. I've played like that for over ten years. So it annoyed me greatly that I can not rebind any key to the numpad. Bloody hell!
No problem I thought I'll plug in my gamepad and play with that. Only to see that my character keeps on turning. The same problem occurred with the new Batman game. Looks like these games only work with an Xbox 360 controller. No, I'm not gonna spend €30 on a controller for a game I spent €5 on. At least Batman: Arkham Asylum worked flawlessly with the mouse & keyboard. But too often console games are ported in a hurry. Sometimes the port is done so lazily that even the on screen commands aren't changed. If you're playing with a keyboard you'll see "Press x on your controller".
I could use an external interface program that catches the keys and sends them to the game as a different key. But I really can't be arsed to spend an hour rebinding my keys while I could use that time to play a game that does allow me to bind my keys wherever I want.
Some games set a nice example. I could bind all my actions to the numpad in World of Warcraft. I could even bind my actions to a combination of alt/ctrl and numpad. Binding control to my mouse thumb button gives me easy access to 36 actions. More then enough for any game. If your game needs more then you should take a good look at your interface.
Developers often seem to forget that not everyone plays like they play. Not everyone will play with an Xbox 360 controller or use the WASD key combos. Some people are used to play with an inverted Y-axis and have been playing that way since the nineties. And other gamers want to have a mouselook.
So please give the players the option to play how they like. A lot of people, including me, will not throw a decade of muscle reflexes overboard just to play your ten hour game. After all, is it really that hard to give us the option to bind actions to the numpad?