And you can't use Wii for pretty much anything else. Surely you could "buy" a browser with Wii-points (if they haven't made it free already). But the web-browsing experience is also pretty lame. And you can't use it to watch movies.
So I bought a Wii because it was cheaper at the time (not anymore). But you won't catch me buying any games for it. I just borrowed some games I didn't like and now it's just sitting there ... and from time to time when a friend comes I just take out the free "Wii Sports" that came bundled with it.
If Wii really outsels Xbox it doesn't say much because they target different markets.