Well you know it's not compulsory that you must buy it. There are other options you know.
not at all. i don't want to upgrade my phone each time something comes out, and the old one is still ok. i just home there will be a "regular" sized iPhone in the future. i'm quite happy with the 5s, it has the same snappiness as 4s had with ios6.
i like the ecosystem, i like how it works together with all my crap at home.
if there'll be only 4,7 or 5.5" new iPhones in the future, and my (then) old 5s says goodbye to me, i hope they will be still selling some older model too, like they do it with iphone4S right now.
coz it is highly unlikely my hands will grow any bigger now