The whole arguments of iOS 7 spurring planned obsolescence comes from the theory that the transitions, parallax, etc. etc. were done not only from a design standpoint but from an inferior-hardware-can't-replicate-this standpoint, which I believe Gruber propagated himself (though in reference to Android, rather than older iPhone models.)

I don't think anyone is arguing that Apple added those features solely because they perform poorly on inferior hardware. Perhaps that's a side effect, but Apple openly concedes that, as evidenced by graceful fallbacks included in the operating system which turn off features such as blurring and parallax on older devices, as well as manual options to disable various hardware-intensive aesthetic improvements.