The problem is it's dickery, pure and simple. There is no technical reason those add ons can't run on the 4-non-S. I'm running a freaking Siri app from Cydia and it works just as well as the real thing. The battery life isn't reduced any appreciable amount, the phone isn't slower or more prone to running out of memory.

Yes yes I know Apple doesn't owe people free upgrades. It still bugs me.