I regard lawns as bad because they are like concrete to most species and have very little benefit for wildlife. But are lawns bad, considering all the other activities and consumption patterns we urbanites partake in?
Trees and plants help cool the city, which reduces the need for energy-hogging air conditioners while also providing valuable ecosystem services like reduced water runoff, filtration, and habitats for city critters.
Once a big idea is vetted -- whether in an authoritarian or democratic way -- what assures its success? Most particularly, what if, from Day One, the vision pushes comfort zones of the achievable; politically, legally or monetarily?