Why would Valve be interested in selling this to people with a gaming PC? Those people already play games on a PC, and are unlikely to give up their keyboard/mouse setups.
Thanks for the downvote and not understanding the concept.
Many console games outsell their PC games, PC and Console games can both reach the same graphical qualities. A lot of poeple play PC games with a controller because it's so much easier than with a mouse and keyboard (except for sim games, strategy games, and first person shooters). In many cases the only difference between console gaming and PC gaming is the setting. Console gaming takes place in a living room with a big screen tv and nice comfy chairs with room for others, PC gaming takes place in your home office or personal room and it's not as relaxing or natural feeling nor is there room for others. So by streaming a PC into the living room instead of buying more hardware to maintain and take care and hook up and make room for. Just stream your $1,000 PC to the living room.
Your scenario is highly unlikely.