These are upscale areas. You wouldn't allow pig farms to be built atop people's houses, why ugly power plants? Solar collectors are industrial looking and don't fit in with expensive houses.
There are pigmented solar panels that come in other colors other than silicon purple. Was developed by DoD for concealment and is now entering the builders market to meet architectual and esthetic needs. I do not think one should put solar panels on a house to recoup high energy costs. I see it more as an emergency power source if power goes out over a long period of time (i.e Hurricane, Earthquake, or other major diseaster). Beats a generator which needs gasoline and operates for 4 to 6 hours before it needs refueling. The problem is if you add $ 27000 value to your property, the property taxes will go up.