Valid concerns and desires, but none of means jack all unless the thing has a ton of games to play, which it won't. Not unless Linux significantly changes and catches on in the next year.
Maybe Valve will be the driving force behind it. If nothing else, make their own gaming-orientated "Linux variant" that only they supply. Most likely Valve is still trying to figure out themselves how to deal with Linux, this is all still experimenting I think (introducing a gaming "console" of their own based on Linux, and at the same time dabbling in desktop Linux gaming).
After all, most smartphones are nowadays also running "Linux", or Google's idea of a proprietary OS whose roots are in Linux.
I just see this as Valve's desire to stay as one of the leaders, not followers (who just take any scraps that drop down from Microsoft's table). If Microsoft hadn't introduced Windows Store/"XBox Games" into PC desktop, I presume Valve would have had much less desire to change their current market status.
Someone earlier had a very good point that if they used e.g. Windows in their gaming console, then they would be still totally in MS's grasp, which also happens to be their main competitor in the gaming console realm. Not a good position for Valve, if they really want to stay in the competition.