Excuse? Erm... family orientated console, lifestyle games (Fit), motion controls (doing something different), fairly cheap-ish in comparison, most worldwide sales than any current gen console. They may not have innovated with "super dooper graphics and 3 millions processor power RAWWWRRR", but there are other ways to innovate.
I've said it before and I'll say it again. For those slagging off the Wii for whom the console doesnt appeal to then thats because it was never really supposed to. I'm pretty sure they weren't targeting the hardcore gaming market. IMO.