I agree with Asha they dont have to worry about a different variety of systems on consoles they know what they are dealing with and constentrate on the game itself more. Im not saying PC games dont pay attention to story lines or content cuz there are some great games that do that but after they do all that they have to figure on what types of systems can run it smoothly without the consumer having to go spend more money.
I was waiting for Halo to come out on PC too, like many others, and thought man this is going to be hard to do without a keyboard. But after a bit of playing it I got use to the controller and loved it! It is nicer playing with a keyboard but the controller is nice when you get use to it. Its your brain that has to get use to using a controller over a keyboard, just an adjustment
.