Disappointed is a strong word. I wasn't disappointed per-se, but it could have been better.
Overall, I feel like there weren't a whole lot of games that were really 'worth' it. The library to me remained quite shallow throughout it's life. However, what it lacked in quantity, it did make up in quality. For a lot of franchises, the system did have either the best or one of the best entries of that franchise ever. Both Zelda's, both 3D Mario's, Kart, some of the Wii-games and some others were instant classics. In that way it's better than GameCube for sure, so there's a rising trend for now, which to me both didn't have the quantity or the quality.
The system had more potential, and I feel if it had even just 50% more power, it would have made a bigger impact. Not counting WiiU, I'd say it ranks 4th behind N64, SNES and NES, but before GC.