[tediousdemise]

I’d reckon it’s the same reason that there isn’t much of a custom laptop scene. The open ended nature of stuffing a screen, battery, and input peripherals into a chassis seems an order of magnitude more difficult than just making a headless box to plug into your TV.

But with some effort, it would be awesome.

[jonny_eh]

Physical design is also a lot more important. Getting "feel" just right is very hard and expensive, especially when it comes to game controllers.