I'm not a big fan of people who are always on their phones but I don't think disallowing them on planes really solves any actual real world problem. Those chatterboxes who need to be talking will just continue to annoy the stranger sitting next to them or chatterbox with their friend sitting next to them if they are travelling in a group. Either way I need to filter them out with headphones or whatever.

And while I have no interest in spending the majority of even a short flight talking on phones, it would sometimes be very convenient to be able to make a quick call to someone waiting at the airport 10 minutes before a flight lands or something like that. Throwing out that sort of convenience to get rid of a distraction like someone talking on their phone in an environment that is already inherently full of really loud sound distractions seems like a silly move to me.