They're not. I think it's more difficult to make the argument that an XBOX is used for general computing purposes (and would therefore warrant a great level of activity, activity which overlaps significantly with what you would do on a laptop/desktop) than you would for an iDevice.

Though even amongst iDevices you can make distinctions. It's pretty blurry which is why I think the OP seems to be right (though not at that extreme), but I don't think including the XBOX would be a good enough offset.