Of course there are some instances whereby a camera would be quicker, but overall, those instances would be few and far between when compared to how easy TouchID is.
- Phone is on a flat surface. I reach for it whilst my face is turned away. Screen is unlocked.
- I'm in bed at night - the light is switched off. I reach for my phone. Screen is unlocked.
- I want to use Apple Pay on one of the public transport stalls. If I had to face it, I would have stand to make sure my face would be within the camera's range. As it stands, I can get through the stalls within 2 seconds. I don't need to look anywhere - I just extend the phone and walk through. Using a camera would slow that down.
So if we compare the cost and benefits of the two, it's cleary that there are fewer benefits and greater costs in replacing TouchID with cameras. If Apple can show us a different technique that would remove the costs as mentioned above, then I will be pre-ordering my phone iPhone 8. I am not, however, going to pay money I work hard for in order to accept a step back, and be a martyr for "technological advancement".
I would like to think that too, but considering their recent hardware changes, i.e. the Mackbook Pro, I don't know anymore. I don't think we can give them the benefit of the doubt anymore.