I think this statement is pretty much the line between people who live in urban areas and people who don't. If I was living now in the town I grew up in, where there is no public transit except the school bus service that runs door to door for every kid up through high school, and we had a land line in the house, and DH and I didn't both work full time, I wouldn't feel that my kids needed phones.
We gave up our landline the day that the line fell to the sidewalk across the street, and the phone company told us it would take five days to get it repaired. I live in a city where kindergarteners are routinely assigned school bus stops half a mile from their homes. I have arranged for my elementary school child (age 6) not to be on that bus, but if he was on that bus, he would carry a phone now. Twelve year-olds in this city take the city buses to school, and I will want my child to have a phone when he reaches that stage.