I think his point is that the Wii has little interest if you don't have people around. That does limit its validity as a "real" gaming system, as it's not really the sort of thing an avid gamer would sit around and play. I'm not putting the Wii down, I enjoy it, but I think what emeraldfool said about it's restrictions is fairly valid. I would love to play it with friends, but I'm not going to own one because unless I have friends over all the time, I'm just not going to enjoy it that much.
I find it's particularly a good system for people who live in dorms and have nothing better to do with their time than have people in their hall come over "for a game of tennis".