The phone ringing has nothing to do with the iPad - it's not a phone, and it doesn't ring. It does, however, make annoying alert sounds. Or worse (if you pick it up, turn it on, swipe to unlock, and find yourself in some app that resumes loudly - though at least in that case you can use the volume rocker - but not before the noise starts.)
I was responding to the claims that there is a need to be able to quickly mute the iPad. The only reason to need to do it quickly would be if it was eminently going to generate a sound. One example was given by people predicting Facetime for the iPad whereby the iPad would indeed ring like a phone does.
And your second paragraph is mere conjecture. If you are relying on this thread, that proves nothing - it's a self-selecting group.
No, it is not mere conjecture nor is it based upon the feedback in this thread.
I have been involved with selling iPads, training on iPads, and providing support for iPads for the past six months. I have interacted with literally thousands of iPad users.
And the urgency with which the screen needs to be locked is not anything like the urgency with which the sound must be muted - with one, even with your fake manufactured scenario, the extra screen orientation locking steps affect only the small number of people in physical contact with the iPad.
My example was definitely not a fake manufactured scenario. It happens several times a day with a very significant number of iPad users.
For screen orientation, urgency is certainly not the right word, but the fact that the screen orientation is changed much more frequently makes efficiency more important. When you have need to lock and unlock and re-lock screen orientation repetitively, the value of a single hardware switch increases exponentially.
I can not imagine even a fake manufactured scenario where an iPad user would need to repetitively mute and unmute and remute their iPad.
I would hardly describe any sound from an iPad as loud.
Regardless, the examples that you describe do not require muting to happen quickly. Once the iPad has made a sound, you have already been disruptive and are already embarrassed. It is irrelevant whether it takes you 1 second, 10 seconds, or one minute to then mute the iPad. The negative repercussions from you failing to mute the iPad before you entered the room cannot be erased by the speed of muting after the fact.
However, the negative repercussions of having to repetitively "double-tap, swipe, tap to screen lock" several times during a 20 minute exchange can be completely eliminated by leaving the hardware switch screen lock theway that it is.