I don't like containerisation because it leads to bullshit like atomic distros. I don't want a spicy Android.
Steam OS has some cool elements like the menu, the in-game side panels and the game mode/desktop dichotomy, but incremental rolling release is utterly deranged from my POV as an Arch user (btw).
Say Plasma "breaks" - a wiki will not help fast enough.
I'm not trying to defend rolling release for a gaming console, but give me at least the option to decide for myself whether I'm ok with breakage or not. There is this kernelspace NT driver that I wanted to try, but I couldn't because pacman is locked.