Yeah, it is, but be patient with the folks: Many of them are buying their first console since the Atari 2600 or their first console *ever*. Without them, the Wii wouldn't have sold as mind-bogglingly well as it has.
Videogames are becoming mainstream entertainment for all ages, and we're in the "blinking VCR clock" phase. I'd bet many Wii owners connected to the Wii Shop for the first time because of TB:RB. Hopefully, those numbers will grow.
I'm one of them I had a 2600, and then the 5200. After that, I only did gaming on the PC. We only bought a Wii after the wife got interested in the Wii Fit stuff. Had no need or desire to get online with it till TBRB, and then only to get the DLC. And that's the only online usage it's had. If all additional songs for TB were released on disc instead (or as well), I'd never bothered to connect it.