Because it's too darn fun.
For the very few people who do not know, you can download the free demo here:
http://www.spore.com/trialThe
actual Spore game is coming out on the 4th of September for Australia and Europe, the 5th for the United Kingdom, and the 7th for North America.
So in this little game you take objects from the object bin and on to your creature. You can make it look like whatever you please. After you're done placing all your objects, you get you paint your creature. Then, finally, you can bring it into the test drive and play some of the animations available. After you save it, you can upload it to your Spore page for everyone to see and download.
This is my Spore page. c: Share your creations!
OMAIGOD SOMEONE MADE A PENGUIN