I think it's because they want to think of it as a system, not "just" a device. You never use the definite article before an operating system, for example, or a

I think it's because they want to think of it as a system, not "just" a device. You never use the definite article before an operating system, for example, or a piece of software. "Download music on iTunes", "manage your photos with Mac OS X", "read the morning news on iPad". It does sound damn weird though.