Yea I understand people upgrade for different reasons, but let's look at it this way. I have the iphone 5 which the newest design and newest ios. The iphone 5s will have the same look, but will be a bit faster I guess. I am not sure how much faster the phone can get. The iphone 5 is crazy fast. There will mostly likely be some new features like siri or something that the S will have that 5 does not have or will get. Is that enough to upgrade a phone?
From that side of things it just does not seem logical.
YOU (because you have an iPhone 5) are the not the target consumer for the 5S. They assume that if you purchased the 5, you are again locked into contract for the next 2 years and will need to wait at least a year (most probably 18 months) to upgrade again.
Apple simply plays to the carrier upgrade schedule which leads to more major updates every two years as opposed to every year.
And as I said, is there really any technology that would require Apple to release major updates every year? People love the look of the iPhone hardware - widely seen as the best out there. Should they simply change it for change sake?
If it ain't broke....