You're not being reasonable
Ever since it came out, it seems like Wii Play has been somewhere on top of sales charts and even managed to be the #2 top-seller of 2007 in the US. Let's be clear about this: even if it looks like a good deal, being only $10 above the price of a standalone Wiimote, it really isn't. It would be a good deal *if* Wii Play itself was worth $10, which it isn't by a very large margin (i.e. at least $10). As a matter of facts, if you gave me $10 to play this thing (which I refuse to call a game), I would decline. And I want the fifteen minutes I spent trying to play it back.
The only person in the family who found this of any interest was my daughter but that's probably because she was 3 years old at the time. By buying this, you're sending the following message to Nintendo: "I'll buy anything from you, so please make more mini-pseudo-games that most sane persons would refuse to play if they were free internet Flash games".
Do yourself a favor: don't buy this thing and just go for a standalone Wiimote instead. And while you're there, pick up a copy of Super Mario Galaxy. Now that's a real game.