I think you'll find the cost to underground services is what's holding it back. And by "we" do you mean that CORA group in Wellington at the turn of the century? What happened to them?
I also recall speaking to lots of people around that time and very few were unhappy with the cables (most people didn't care - "Saturn's cable blocks my view...of the other cables?"), but they were certainly happy to have faster (cable) internet.