A thief flags you down, grabs your phone and makes you unlock it using your thumb.
A cop opens the cop car door, grabs your hand and unlocks your phone, or even easier, face unlock.
Granted, guns and torture are rather effective as well, but is anyone entirely against fingerprint unlocking?
I don’t use it at all, even with various bank apps and such yelling at me to do so. Yeah, a $2 wrench could still eventually get it out of me, but you can’t just use my face/finger to do so.