Maybe I'm dating myself here, but multiplayer games are still newfangled and weird to me, and I don't know if that will ever change.
When I used to play games, I played to get away from social interaction and enjoy myself in isolation. It was a kind of recuperation. A world of gaming in which you have to face social interaction once again as part of gameplay was unattractive enough to me that I stopped playing games altogether. These days I mainly do crossword puzzles and read e-books for the respite that I used to get from gaming.
Well you're not alone, when I was much younger I enjoyed competitive FPS's, multiplayer, LAN's, and all that. But as I've gotten older I enjoy single player games more so than anything else because as you put it, it's a form of recuperation and you can decide "how" you want to enjoy yourself.
But as a point, there were articles back in hmm 2004 or 2005ish declaring the "end of single player" as well. Strangely enough, single player games are still going strong. And when developers shovel multiplayer into single player content many don't like it. One of the better examples of this would be Mass Effect 3, where they attempted to shove you into MP so you could get the best possible ending. It didn't take long before it was patched out, and the amount required reduced. I expect that the new Dragon Age game will suffer the same fate if they try to shovel something in that "makes it a requirement for a good ending."