Enforcement of air travel rules is strangely inconsistent. Every person on the plane could have their phone on in their pocket without Airplane Mode and no one would know or check (and because they aren’t going seat to seat demanding proof of Airplane Mode, I always figured it couldn’t really be a safety issue).

Heaven forbid you don’t take off your shoes at security though, what kind of monster are you?

While it is true that cell phones in planes put more burden on access points, it has nothing to do with an FAA regulation. Why would the FAA care about a private telephony company's equipment?

The FAA regulation was always about interference, plain and simple. The fact that it took so long to change the rule is basic regulatory sclerosis.

The point of this answer is precisely that there is no FAA regulation on cellphones, which seems to be supported by this Wikipedia article: https://en.wikipedia.org/wiki/Mobile_phones_on_aircraft

    > Contrary to popular misconception, the Federal Aviation Administration (FAA)
    > does not actually prohibit the use of personal electronic devices (including
    > cell phones) on aircraft. Paragraph (b)(5) of 14 CFR 91.21 leaves it up to the
    > airlines to determine if devices can be used in flight, allowing use of "Any
    > other portable electronic device that the operator of the aircraft has
    > determined will not cause interference with the navigation or communication
    > system of the aircraft on which it is to be used."

But why would airplane systems be vulnerable to interference from mobile phones? Wouldn’t that be pretty much a show stopper? Yes

Why the difficulty in updating the regulation then? Seems like an easy fix.