Earlier quoted context omitted.
The streaming works if you have a beefy Windows machine in your house already, it's not a solution for people wanting a dedicated "Steam" console.
It is a brilliant tactic to migrate the considerable Steam base to the Steambox. It is transitional, of course, but brilliant for it.
Old Way) I have to spend all the money for equally good hardware. I also need a copy of Windows.
New Way) Just get something that can render YouTube videos well. I now have a second Gaming PC. No copy of Windows!