To resolve this issue, I present this modest proposal.
Remember back in the days when smoking was permitted on airplanes? When you bought a ticket, you were asked whether you wanted to be in the smoking or non-smoking section. We can do the same thing with mobile phones. You can ask to be seated in the "yapping" or "non-yapping" section. If you're in the yapping section, then yap all you want. Call your grandmother and talk with her the entire flight about her colonoscopy, see if I care. On the other hand, in the non-yapping section, the phone stays off.
This principle of yap-or-no-yap can be extended to other in-flight disturbances. The no-yapping section would be renamed the "quiet section", where electronic devices must be muted (or used with headphones) and conversations must take place at low volume.
(Hey, it worked for Amtrak, it can work on airplanes.)
Side note: I wonder if the temporary ban on carry-on luggage in the UK improved airplane boarding times. Perhaps we could ban carry-on luggage across the board, not as a security measure, but as an efficiency. I don't know about you, but I'm really anonyed by those people whose "one carry-on bag and one personal item" consist of a carry-on bag the size of a small refrigerator and a personal item the size of a microwave oven. They clog up the aisle for ages trying to heave both of their bags into the overhead bin (even though the personal item is supposed to go under the seat in front of you). Okay, enough ranting.
Next time (if there is a next time), I'll solve the problem of steroids in baseball.