Why won't they allow cell phones on planes?

Notice that this post is filed under "Economics."

The airlines fear "crowd control" problems if cell phones are allowed in flights.  They believe cell phone calls might promote rude behavior and conflict between passengers, which flight attendants would have to deal with.  The airlines also benefit in general from passengers remaining ignorant about what's happening on the ground during flights, including personal problems, terrorist attacks, plane crashes and other information that might upset passengers.

This is also relevant:

However, the airlines know that some kind of plane-to-ground communication is coming, and they want to profit from it.  Simply allowing passengers to use their own cell phones in flight would leave the airlines out of the profit-taking.  Airlines would prefer that phones be banned while they come up with new ways to charge for communication, such as the coming wave of Wi-Fi access.  Meanwhile, the ban is potentially more profitable.

Here is more.