Same reason Detroit doesn't have useful mass-transit.
Entrenched interests make more money by prolonging the problem. Arguably the solution would be economically superior (vastly so!), but the folks who'd profit from it aren't in power _now_, and government lacks both the technical competency to understand what to do, and the balls to do it.
Entrenched interests make more money by prolonging the problem. Arguably the solution would be economically superior (vastly so!), but the folks who'd profit from it aren't in power _now_, and government lacks both the technical competency to understand what to do, and the balls to do it.