The point he makes is that he wants single-player that will work independently of an internet connection, and independently of utilities like Steam, for various reasons. In this I agree with him, not because I dislike multi-player, but because I often play when I have no internet connection available.
I'm pretty sure that my single player Steam games work even if I'm not online.... it doesn't require you to be online to play them unless its an online game.
I fear anyone who wants to remain utterly disconnected in an ever more connected world is fighting something of a losing battle....!