Daring Fireball Apple Addresses Why Some iPhones With Older Batteries

I always found the argument that Apple purposely slows down phones ridiculous, turns out they are, to some degree, but it’s to improve device longevity.

As Gruber puts it: 

If older iPhones suffer upon being updated to iOS 7 — getting slower, or worse battery life, or losing Wi-Fi — to such a degree that the users conclude they now need to buy a new phone, would not the most likely and logical result be that it would inspire many of them to switch to Android (or Windows Phone, or anything) rather than to buy another iPhone?