I just reset my fingerprints yesterday (since never altering them since I got the phone in early October) and my TouchID is back to working flawlessly. It was taking at least 3 touches to open my iPhone from the lock screen and now it's doing it automatically.
putting in my password is also faster than the try again I get at very very least twice a day.
It doesn't have to be like this though. If you are having to repeatedly touch it, try registering your prints again. You'll be pleasantly surprised.
And setting your lock screen to 15 minutes is asking for trouble. TouchID allows it to be immediate, the way it should be for the best security.
I read about scanning the same print twice about 4-5 weeks ago. Ever since then it has been 100x better.
The problem with Touch ID is not a problem with Touch ID. It's a problem with your finger.
Especially this time of the year for many of us north of the equator - it's winter. This means our fingers are drying out and causing poor accuracy when it comes to Touch ID:
I can repeat this issue EVERY morning. Every morning I wake up and reach for my phone to check my messages. I know that Touch ID is going to fail a good 40-50% of the time when I do this. After I've been up for a while, this accuracy improved to 80% (in December). If I go and have a shower, immediately afterwards accuracy is probably around the 30% region. However, after my fingers have re-shaped themselves to normal after the long, hot shower, accuracy is at 100%.
My hands are HYDRATED at this point, but not shriveled anymore from the shower. This gives me absolutely 100% accuracy. My wife finds the EXACT same thing to be true with her 5s.
My suggestion to most people is to have a set of spring/summer fingerprints, and a set of fall/winter fingerprints.
Blaming Touch ID isn't "entirely" fair, though I guess it's Apple's fault to a large degree for implementing a security system that involves an ever-changing part of the body.
The problem arises when TouchID tries to "learn" and adapt to this alteration in the ridges of your fingerprint. To me, this is muddying the water and a recipe for disaster. When you keep adding "fingerprints" (wet ones, cold ones, hot ones, dirty ones, (de)hydrated ones), you're bastardizing what you true fingerprint is and getting further from what your print really is. For me, I believe it's the "learning" function that leads to TouchID inaccuracy.
I have not seen any "working" proof of Touch ID learning anything. My finger works exactly the same now as it did day one when I got my iPhone 5s (launch day). The weather/bath/shower, for me/wife, has been the defining factor.
Have you guys tried actually using a microfiber cloth and cleaning the actual home button?