To some degree I understand a bigger screen on a phone, I wasn't really too sure about the idea but essentially this is the way phones are going and as long as it doesn't become ludicrous then I do see the potential of a bigger screen.
Well I guess that depends on what you mean by "ludicrous." At one time, just a few years ago, 4" was a big phone. Then 4.3. Then 4.5, 4.8, then we broke 5. Now we're apparently at 5-6.9. I'd say we crossed ludicrous some time ago. I honestly can't help but laugh when I see someone placing a call on something like a Note.
If apple wants to go a little bigger, like 4.something, that sounds good (I trust they'd do it right). But past that, it reaches a size that is just not practical for pockets, smaller hands, one handed operation, etc.