My wife is an urban land use planner. When I try to explain that to people, I usually say, "She plays Sim City for a living, only with real cities." When that fails, I tell them that she's the person who argues your case whenever you want to build or remodel a building and the local zoning officer says you can't. That's not entirely accurate, but it gets the point across.
In New Jersey, planning law is administered on the local level, and there are times when that local focus can make it hard to render a decision with a bigger picture in mind (like how a proposed shopping center or power station might be a bad idea locally, but a good idea regionally). Some argue that planning law should be administered on the state level, to enforce more consistent standards and interpret planning law in a broader context. But that would overlook the nuances that inform local planning decisions. The state would be a distant authority with no real investment in living by the decisions it hands down. And really, why give Trenton one more thing to screw up?
It is unclear if state planning rule will ever displace local rule. Were it to happen, there would surely be a big dust-up over it, and I have to imagine that for a lot of people, the results would not be worth the fuss, especially considering how uncertain it is that state rule actually would work better than local rule. But the thought of it lingers, like an itch you can't scratch.