I said this before and I'll say it again - probably at least 75% of all linux steam users are also using the windows version. If you were to reduce the count of windows users by the count of linux users, I'm sure the percentage might increase to almost 2%.
I would have to say, I'm pretty disappointed there are so many 32 bit linux users out there. Seriously, are all of you running P4s?
FWIW I got the survey on the Linux side yesterday so I doubt there's a bug in there.
The results are pretty pathetic but not surprising. It seems to match the overall desktop trend. It's interesting to see that the unreleased Windows 8.1 has about as much marketshare on Steam as all of Linux combined.
It's probably what we all know... The Unity / GNOME Shell debacle pissed off a lot of people and they went back to Windows... or moved over to OS X.
Really? Last I heard was that they all switched to Cinnamon and Mate on Linux Mint.