"I should really get around to snagging a Wii one of these days...unfortunately, as you say, you usually need friends to come over to play the damn thing"
The Wii used to come with friends.
Now everyone's tired of the Wii, so nobody cares about who has a Wii.
Honestly, I think the purpose of the Wii was to make gaming a social experience again. I think they've accomplished that, but the people who play the most games are the ones who want single-player games.