There's no question that Touch ID is meant to be a convenience feature, not a serious security feature. Simply, all biometric systems can fail in a variety of ways, and no serious security system would be based only on a single factor biometric system. As Schneier says, adding a guard with a big gun to prevent messing around is very effective.
Also, this is completely true:
The iPhone does not do this.
Full disclosure: I'm the CEO of Bionym, which makes the Nymi. It's a 3-factor authentication system, and the idea is to build a chain of trust between the user and a wearable device (the wristband), and then the wristband securely communicates identity (not biometric data) to other devices. The biometric is only utilized to secure a short section of chain of trust.