I'm not surprised.
I usually try to judge these things based on anecdotal evidence, and from that perspective the iPhone 5 is a flop. Of course it depends on my location, place of work and a billion other factors, but in a modern busy city you see a lot of random people with their phones and occasionally you notice one.
I don't tend to see a lot of iPhone 5s around.
Personally, I'm not tempted to buy one, either. The iPhone today does basically the same things the iPhone 4 did, just faster. The iPhone 4 was as big of a shake-up as the iPhone's had since launch (and even then it was a new case and faster internals).
There hasn't been anything revolutionary. Nothing that really pushes the device to the next level or provides something radically different. NFC could do that, but in that case it's less about physically sticking it in to the phone and more about building up the infrastructure; unfortunately Apple doesn't seem to be doing anything there, and they don't seem to be doing anything else either.
As always, would love to be wrong, hope they have something really great. Unfortunately when you build your brand on innovative ideas, people expect you to keep delivering. When those ideas run out your brand will just lose steam.
That's because the iPhone 5 _is_ the iPhone 4/4s. It's the 3rd generation iPhone 4.
The next one will be the 6 and 6s and the 7 will be the 3rd generation 6.
Then 8 and 8s with the 9 being the 3rd generation 8...
I'm ready to smell my own farts when the next iPhone is named and revealed...