People do this all the time. There is even a name for it in the industry, "killer app." It gets you to buy the hardware needed to run it.
People see games and buy consoles all the time, it's literally what gets a console in to all our houses. There is a game we want to play. Eventually, regardless of your initial reason for buying it, you will end up buying more games. Because you now have the system.
@ other dude,
I say go for it man. Get the Wii U. Online is crazy fun. Also if you have a nice sound system, the game sounds amazing.
I bought the Wii U only for MH3U, but since we have one now, my gf bought Pikmin3 and while I personally wasn't interested in it, and never played it before I am super happy that we have that game. It's really fun.