My thoughts on this is that I want to see evidence that modern phones do not cause any interference. While clearly a mobile phone being used won't instantly down a plane
My understanding is that in the airport industry the target is zero accidents. So, even if there has not yet been an accident yet, if there's the possibility that there could be an accident due to the phones, and airline safety is a very well studied field, then a ban is reasonable.
Even if the only effect of the phones is to distract pilots a bit, well there are safety procedures in place where the whole point is to avoid pilots being distracted at critical times. So, again, I could see that it's plausible that a ban would be sensible even if that's the only result of the ban.
However, people's sense of entitlement concerning using phones is such, that the only resolution I can see is that planes and plane communication systems are going to have to be built around the concept that people will use their phones no matter what.
Note: I am not assuming that a ban is necessary. See my first sentence where I say that I'd like to see firm evidence one way or the other as to whether phones actually cause a problem.