It's not Steam we should care about, what we really want is Source for Linux. And GoldSrc for that matter, I'm sure some people would like to play Counter-Strike.
"Source" is the brand name of Valve's game engine, used in the Portal and Half-Life series, Team Fortress 2, etc. "GoldSrc" refers to the legacy version of the engine used in Counter-Strike, Half-Life, Team Fortress Classic, etc.
In my case, TF2 and Half-Life are the only things stopping me switching to Linux as my main OS. I can agree with you there, I want to be able to code and game on the same OS.