9. Spectravideo's Compumate
Spectravideo's Compumate was designed for the Atari 2600 and released in 1983, because Spectavideo made the rather asinine assumption that just because people were into video games, they'd also want to dispassionately learn how to program stuff too. The Compumate was a relatively rudimentary bit of kit that was essentially a keyboard with some computer components inside, and hooking it up to your Atari 2600 allowed it to become a BASIC programmer. It's difficult to see how you could market something so soul-crushingly banal; it's not like the allure was even about making your own games, but really it was best capable at writing small, basic general-purpose ones instead. While the nerd elite might have had paroxysms at the sight of it, for the average gamer, it was just that most bizarre and esoteric of peripherals, and certainly not one they would want to play. If I want to program, I'll buy a computer, thanks.