No it seems YOU don't understand. Just because it 'should' doesn't mean it will. It is working as it has been for the last 4 generations of iOS. The only difference is that TouchID is faster with the 6s and 7. Therefore, if you click with the home button you will be taken to the home screen, no matter what, because it authenticates immediately. I learned to use the lock button last year with the 6s to prevent this, that same behavior has carried over to my iPhone 7Plus now.
Again, the "Rest Finger to Open" Applies ONLY to using Raise to Wake and waking the screen with the lock button. Has nothing to do with home button. I don't know how many times this has to be explained. "Rest Finger" has nothing to do with awakening the iPhone itself.
Just because it's been that way for 4 generations, doesn't mean it has to stay that way.
Touch ID is simply TOO fast on the new devices and I THOUGHT that was part of the reason for the lock screen redesign.
It seems inconsistent to me.
For example:
NO touch ID = Press home button to wake the screen, press home button again to go home
Touch ID = Press home button to wake screen, keep finger on home button and it takes you home
Touch ID + Rest Finger to Open = Press home button to wake screen, keep finger on home button and it takes you home.
Why are the last 2 exactly the same function? One would think that if you do NOT want your phone to go home automatically by simply holding your finger over the button, then one would turn OFF "Rest Finger to Open" and EXPECT the same behavior as NO touch ID.
THAT'S my point. It doesn't make sense why it lets you rest your finger to open when you do NOT have that option turned on.