More likely, it was an attempt for Steam to compete with consoles - Steam can run on HTPCs with Big Picture, but consoles are (or at least were) all about the O

More likely, it was an attempt for Steam to compete with consoles - Steam can run on HTPCs with Big Picture, but consoles are (or at least were) all about the OOTB experience. It makes a lot of sense to simply ship a pre-configured OS when pushing HTPCs. You could say that making it Linux-based shows that SteamOS is all about Windows, but if anything that logic suggests it's all about the Xbox. If it were competing with Windows it'd be a KB+M-based distro. If you say "but they didn't need a separate Linux distro, they were already focusing on Ubuntu", that just proves that SteamOS wasn't about Windows.