It does, they are selling this for people who didn't get the original Wii Fit. There's nothing stopping you from buying a used Balance Board (if you can find one in stock) to play with the game. They do sell the game by itself. Hell, you can even transfer your save data from the older games to this one if you want.
The problem is the game is INSANELY overpriced. This is basically Wii Fit + with a very modest online leaderboard added and a few new activities and dances added. Considering that Wii Fit Plus was just a very modest upgrade of Wii Fit, this is essentially the 3rd time they've released the same game, and asking $60 for it is completely asinine (even if it does come with that broken PoS pedometer).
If you missed the boat where you could buy that $20 pedometer and get a digital copy of the game for free, then I'd skip this game altogether unless you are a massive Wii Fit nut. It's really not that much of an improvement. $55 for a Balance Board + game isn't necessarily a terrible deal, but considering you can get Wii FIt + a Balance Board used for under $20 at Gamestop it's hardly worth it IMO.