All someone has to do is assemble a reasonable desktop that runs Linux, gives you access to GOG and Steam, and you've already got more games than most game consoles, the issue right now I suppose would be moreso hardware costs.
You would also want to make sure your Desktop Environment is fine tuned with a controller in mind.
If you can read games from discs, you'd be getting the attention of many people. The facts are that most people have always bought digital over discs but when you take that away, and it becomes clear that they could lose their games forever, everyone wants CDs back.