Debra, tree placement is just as valuable in cold areas too. They block the wind and cold in cold areas. One of the reasons evergreens are so popular as foundation plants for us cold country people. "The Mature Tree" in suburban areas is also a privacy provider that owners love. They do not want to look out their door/window and look at their neighbors.
Frilly I am sure it was a group of things but I am also sure it was held back because of the landscape. It is how it seems to work in this area. Buyers market you could say. Prospective buyers do a lot of drive by and if it does not look like what they want they keep driving. One of the selling points around here that is included in the ad "Mature Trees"
As my side line income I purchase properties with the purpose of renting/flipping. It is amazing the lack of vision people have when they buy houses. I could not believe one woman said because of the way the house was staged she could not tell whether the house was 4 bedrooms or 3 bedrooms. One of the bedrooms was set up as an office. (a desk, Bookcase, etc) When I asked her why was she confused she said because one room looked like an office and not a bedroom. Dah