I wouldn't have the slightest idea on how to even start coding a feature for linux
And yet you are calling me the idiot.
I'm just saying Linux can be whatever the public wants it to be, not that you personally have to code all of the features you can think of. The case is really simple: Valve needed a feature, so they created it and now that's part of Linux and everyone can enjoy it. If you or Valve want something changed in the way Windows or Mac OS X work, they have to approach Microsoft or Apple and chances are they tell you to go jump in a lake. But on Linux, you can just get started and make it happen. How is that not just great?
So Linux might not be there yet for your personal needs. Too bad for you. But instead of being angry or sad about it, you could also celebrate the fact that Linux is open to anyone and therefore adapts to whatever people are asking for. So chances are it will feed your needs in the future. Especially for gamers, with all the weight Valve is putting behind Linux, I think there are great times ahead for people looking to get rid of Windows for their gaming needs.