I'm all for user choice, but unfortunately "choice" doesn't actually seem to be the way the market is trending...
I've been trying to decide what to do when my phone contract comes up for renewal, and want to stay with the same carrier (phone number, contact email, etc).
However, my carrier (au), despite offering 28 (I counted!) different smartphone models, seems to be going whole hog for giant-screen phones, and the smaller phones are all "budget" models with worse quality screens, heavier weight, etc. [The big exception is the iphone, but I want Android.]
The sense one gets is that they consider smaller existing models "leftovers" from the past, and that they'll be pumping up screen sizes even more once they get the chance...
[This is particularly absurd in Japan where hands are smaller on average, and far fewer people drive everywhere than the U.S. (small size and light weight are more important if you've got to carry your phone in your pocket all day as you walk around; if you're driving portability is a bit less of an issue)...]
My first smartphone (late to the game) was a Motorola Droid Razr. It's a little smaller than the SIII, but being my first phone, I just became accustomed to the size.
I use friends' iPhones a lot and the first thing I notice (other than just one button) is how small it is. Those same friends struggle with the enormity of my device.
I think it's a similar context switch from Windows <==> OSX. I think people can grow to like either of them, but using one after years of using another makes it seem unwieldy.