Got to agree with him on this, truth be told. Whilst the Wii does have its share of "proper" games (Dead Space: Extraction, Resident Evil and so forth), its main appeal is not as a gaming system along the lines of the 360, PS3 or PC. I would suspect a good number of the Wii consoles have sold not to be used on a regular basis outside of Wii Fit + Similar "Games", and to give an activity during parties or on a family night.
A lot of the games you see for the Wii are compilation packs similar to Wii Play, platform games like Super Mario Galaxy and in general aimed at a much younger market than the other consoles. Mario Kart, six thousand Sonic games, you get the idea.
Whilst I wouldn't dismiss it as a "toy" personally, I won't be surprised when in a few years the preowned market is flooded by Wiis that people don't want anymore. I'd suspect it's probably starting to happen now but give it some time and there'll be more and more second hand Wiis floating around than you can waggle a wiim... shake a stick at.