This is addressed in the article, ugliness probably isn't causing NIMBYism, but it is contributing to conservationism, which is a slightly different thing, and

This is addressed in the article, ugliness probably isn't causing NIMBYism, but it is contributing to conservationism, which is a slightly different thing, and affects house-building in different ways (most conservationist concerns are not quite NIMBY, as most of the proponents of conservationism don't live in the neighbourhood being conserved).