"A fingerprint of the phone user, photographed from a glass surface, was enough to create a fake finger that could unlock an iPhone 5s secured with TouchID."

"This demonstrates – again – that fingerprint biometrics is unsuitable as access control method and should be avoided."

Via Metafilter, where somebody says:

It might be worth noting that the amount of effort required here seems to be significantly more than the effort required to pick a lock, and we're not all saying, "hey, locks are imperfect, it was stupid of the builder to even bother putting them on my house!"

Something is better than nothing, and no security is perfect.

Yeah, and if only the original owner's finger would work, it would create an incentive to steal the phone and sever and take a finger.