There are some people who are around wifi most of the day so don't really need a data plan.
There are those who don't need to be connected 24/7. The OP's friend could have a build in GPS device in the car so doesn't need GPS of the iPhone etc.
But I think ATT is "fair" in that they at least offer the customer a limited $15 200MB data plan.
That's a lot "fairer" than Verizon's policy that forces $30 data plan on everyone regardless of their amount of usage. Like I said before, Verizon had a limited $15 data plan but they quickly axed that data plan for smartphone because they knew those light users were quickly signing up for the cheaper data plan.