[ericd]

It doesn't drown them out very effectively at the distances you're dealing with in a plane, and cell phones would be worse as people would be talking louder than normal into them. I stepped off a plane an hour ago, and I'm absolutely sure that your proposal would make an already somewhat unpleasant process much worse.

Silence in public places is a coping strategy for crowded environments - it's the least intrusive thing you can do to the other people in your space. It's like the difference between jumping around and shuffling quietly when you're in the middle of a crowd - one may be more fun for the person jumping around, but it's selfish, because it makes everyone else's experience less fun, as their toes get mashed on.

That's really the crux of it. Talking on your cell phone when you're mashed up against other people is a purely selfish act. That's why it will always be considered rude.

[manicbovine]

White noise is a more effective sound barrier in small spaces like planes. This is why the captain's announcements must be broadcast in very high-pitched tones.

Perhaps someone's need for a phone call is more important than my desire for quiet. I don't know, it's completely irrelevant to me because I don't go around looking for things to get offended about.

As a sidenote, I could make your same basic argument about crying babies, and yet nobody would take me seriously if I proposed a ban on babies.