Yes it does make sense. In all cases where Linux has any kind of success, it is in cases where the OS itself is hidden away from the end user and most don't even know or care what OS it is because they never interact with it directly. What Valve is doing is trying to push Linux as more of a general purpose gaming PC where the end user will need to interact more directly with the actual OS (upgrade graphics card, install new controllers etc).
That is not the only issue. Valve is trying to push this as a system where you can install anything you want (yes it is a great goal), except the number of Linux games is a tiny fraction of that of Windows. I find it hard to image every game developer suddenly falling over themselves trying to get a Linux version of their game out. Hence why I say just like all previous Linux console efforts, this will also fail. I say they should go ahead and do it, but ultimately it will just set them back and they will just prove my point. Again.