You're not seeing the big picture. Touch ID isn't just another gimmicky feature, it's something Apple spend a lot of money on. They acquired the company that made the technology, and improved it in a way only Apple could.
Today it's a method to unlock your device, but there is no way that this is all Apple wants it to do. The possibilities are endless. Imagine not having to put your password into another website, instead you just touch the home button. Making a purchase on iTunes? Use the scanner instead of the password, etc.
But that's not all. This could easily be used in a retail environment, where a prompt on your screen shows up and says "Buy foobar for $5.99?". Touch ID does the rest.
Today it's a method to unlock your device, but there is no way that this is all Apple wants it to do. The possibilities are endless. Imagine not having to put your password into another website, instead you just touch the home button. Making a purchase on iTunes? Use the scanner instead of the password, etc.
But that's not all. This could easily be used in a retail environment, where a prompt on your screen shows up and says "Buy foobar for $5.99?". Touch ID does the rest.