Sometimes they are right; "The worst things you can do to a historic building, besides arson, is take out historic windows," says Concord, Mass. town planner Carol Kowalski. We might add that in terms of bang for the buck, changing windows has a really poor rate of return and there are lots of ways to restore old windows, add interior storm windows so that one does not wreck the look of the house.
Other times it is just NIMBY silliness, particularly when there are products that blend in like solar roof tiles (TreeHugger here) or the neat, nearly invisible panel on an 1899 chimney cap shown in the picture (cute idea but not much electricity will flow from that) California, New Jersey and and Arizona now all have legislation that restricts homeowners associations from blocking solar panel installations; where are the rest of the States? ::Wall Street Journal