You're missing the point. These locations already exist, have leases, power, data, and a visual presence. Hopefully paid data will help subsidise these dinosaurs. I haven't used one in almost a decade; it was before I had a cell phone and wanted to call someone that did have a cell phone without my (then) wife knowing about it. Even then the phone didn't take coins, so I had to go into the adjoining dairy (convenience store) to buy card, which I never used up. I sympathise a bit - just a bit - with Telecom as in our neighbourhood these phone boxes are routinely etched or the glass smashed. I have no idea how they've been making money for the last few years.
They did set this network up as free to use for all in the Canterbury area after the quakes, which I thought was nice.