Which is perfectly fine, in my opinion. Everything is more predictable when each player acts in their own best interests. Then it's just a matter of understanding their incentives.

There was a time when no one thought gamers would switch from DOS to Windows.

So what's "questionable" about that? The move seems pretty clear cut to me - it's a defensive move against Microsoft's obvious trend for a closed garden of apps and games.

And Microsoft are just responding to Android and iOS app stores.

Windows 8 may have pushed them over the line, and they may only be moving to Linux in order to make more money. Is that really a problem though? I think it's the breakthrough into the mainstream that Linux has been waiting for for decades.

[0] http://www.phoronix.com/scan.php?page=article&item=valve_ste...

They've only been running all their servers on Linux PC's for upwards of 10 years now.

Then I heard how performance issues. Using games performed (slightly?) better on Linux then on Windows. There was talk about mouse issues on Windows 8 and how some bench marks could be faked.

All this sounded to me was Valve wanted a better gaming environment.

Side note, I don't know how many people would be switching to Windows' store and gaming social features over Steam.

Steam is a basically a middleman for games taking 30% cut of revenue. Of course they're and should be terrified of how Apple eliminated middlemen with the App store and the 30% cut of all sales inside the app. There are things like Xfire for the social gaming features.

In other news, it looks like the XCom remake will soon be in beta on Linux: http://steamdb.info/sub/35236/

Apart from the fact that I'd like to play it, it's interesting because Linux Steam has a dearth of AAA title (although it does have good indie games like Unity of Command).

Of course I don't know for sure but for Valve to back out of Windows the way they did it's definitely a strong possibility. Don't forget "embrace,extend,extinguish".