I think that's more because of Apple's insistence to use iTunes, than their willful decision to make typical PCs the foundation of their company.
I bet one of the big uses for that data center is for a way to do iTunes on the cloud, thereby eliminating the need to tether to a regular PC.
With Apple, as dayglored hints at, thin is in. Not just physical size, but thin-client type devices.
That is a natural for Apple. Jobs is thin.
:-)