You need to open your mind a little bit. Making the iPhone slightly longer without adding significant width would drastically improve usability of the pocketable device. Don't get hung up on all the tweaking around aspect ratios. Instead think about how a wider screen is the best way for Apple to improve usability, especially in landscape mode.
I say this with great sincerity as I'm typing this response on my iPhone right now. The text in this edit pane is too small and the scrolling right and left a pain for editing and verification is a pain in the butt. The key here is how do you improve the users experience without turning iPhone into a huge brick, I don't know of a better solution than a wider screen.
Improvement in Landscape mode. Are you kidding. Yes it will enlarge everything in Landscape mode and nothing in Portrait mode. That is BAD in both modes. BAD in Portrait mode because it is to small now and will make no improvement in text sizes, but does show more screen. BAD in landscape mode because everything will auto fill the screen and you will have less visible on screen, and the keyboard will take more screen space so all that will be left is a sliver of visible page. What we need is more screen width and height in the same Aspect Ratio.