Yes, it is inconvenient to have to pull over to allow a passenger to use the phone (almost like hunting for a pay phone back when), but here is an alternate perspective - As the driver, YOU do not have to worry as much about being in a head-on collision with someone who cannot detach their phone from their face and maiming or killing those kids.
Is emergency call at 50mph a forecast of next to come crash ?
More serious: What about passengers wanting to have a phone call ? Real life example: I am in car with kids and tell them to have a call to check there is somebody in their house.
We need federal laws to mandate that all mobile service providers must suspend service to any device that is in motion at greater than 10 mph, except for emergency calls to 911. A lot of money is at stake, these lawmakers must be able to resist lobbyists and bribes.
Passengers will have to ask the driver to pull over when they want to check their messages. As for train/bus commuters, possibly an onboard picocell base station without a shutdown could be made to work, but would need security that prevents copying into a automobile system.
Pedestrians who stumble down open manholes etc are a self-canceling problem and usually do not take innocent victims with them.
I have observed this effect all of my life and many of your issues have been an ongoing discussion for a long time.
Every technical or social change takes time to propagate through society.
The Telegraph, telephone, television, computer, radio phones, cell phones, smart phones, you name it, each device creates its own transition period.
Good or bad effects can take a long time to determine, but as you point out, it is usually people "miss" using the device that results in immediate and in some cases fatal consequences.
I am afraid that we are stuck with this cycle until we can make a better human being.
I am not confident that we will see any improvement on that subject in the near future.
Just my opinion.