A simpler way to explain this is that for the iPhone 6, it really is a slightly larger iPhone 5 screen, like if you were moving from an 11" MacBook Air to a 13" one. But for the iPhone 6+, it's like moving from that 13" one to a 15" Retina MBP. And as we all know, the Retina Macbooks render at a higher internal resolution and then scale it down to the native one.
I do appreciate the technical explanation, but as Apple has done this before, for a quick explanation it's sufficient to point to the rMBP precedent.
> And as we all know, the Retina Macbooks render at a higher internal resolution and then scale it down to the native one.
I don't know that. Unless you're talking about scaled modes, which do resampling, the retina models render at the native resolution. They will scale apps by 2x that are not capable of rendering at the native resolution (not many).
I do appreciate the technical explanation, but as Apple has done this before, for a quick explanation it's sufficient to point to the rMBP precedent.