Strange.
I put Music on all my iDevices, even my Sony PlayStation 3 (250GB, Slim) has like a GB.
Reason? I like playing music while using Safari or other Apps like Zite.
Size makes no difference, obviously I wouldn't put all 10GB if I only had 16GB iDevice. This is why 32GB should be the standard/minimum for Apple.
My 64GB iPad 3G is what I rely/use the most, I sold my 32GB 3G touch and rarely use my 32GB iPhone 3GS.