Again, why not find a solution which incorporates mouse+kb instead of avoiding it? Would console-ers really be too put off by an elegant solution?
And the problem here is not negligible. CoD series games will be miserable to play with a gamepad versus mouse+kb'ers, and those games would likely be quite popular on SteamBox.
"I don't understand the problem with traditional mouse+kb for couch gaming"
"why not find a solution which incorporates mouse+kb instead of avoiding it?"
It sounds like they feel the same way to do. Mouse + Keyboard is already viable across a very wide spectrum of games. They don't need "a solution which incorporates mouse+kb", because that already is a solution (as you note, there's no real problem there).
However, for those that want a controller experience, there's not a viable solution. Controllers work across a pretty narrow spectrum of games. That is the problem that they're trying to address.
Because at some point, Valve is about making money, and people don't buy consoles and attach them to their tv with mouse and keyboard en masse. If they did, this wouldn't exist.
If you want/need to sell something in the millions, it kind of needs to be least common denominator. Gamers understand controllers as the basic interface for tv gaming, so they will buy them.
Gamers don't buy keyboards to put on their TV's so Valve is being smart by not forcing a square peg in a round hole. They want the Steam Machines to sell. A mouse and keyboard won't sell.
1. cultural expecations. consoles have controller gizmos. people expect it. its a different experience than just running an HDMI cable from your PC to a TV and calling it a day. Its a console. It lives next to your TV all the time. Its supposed to have a controller, because Nintendo's NES had one back in 1985. Cultural expectations and traditions are a powerful force.
2. there are many games that are actually superior to play with a controller than with a mouse and keyboard. Platformer games come to mind. Thats a major genre of consoles and always has been, and alot of indie game companies are exploring the genre again on the steam platform. At the moment I have to use an XBox controller plugged in to my PC to play. If Valve offered their own controller I'd gladly use it instead (assuming its good).
There are certain games that work better with controllers—the best example I can think of is Mirror's Edge. I would be upset if I couldn't use a controller, because sometimes you need joysticks.
Is that even a good example? Mirror's Edge without the speed and precision of the mouse sounds awful for speed runs, and nothing is lost with the lack of an analog stick for movement (since you're always running).
If you haven't tried before, I highly recommend doing time trials with KB+M. It's a completely different game.
And the problem here is not negligible. CoD series games will be miserable to play with a gamepad versus mouse+kb'ers, and those games would likely be quite popular on SteamBox.