As we know, most older courses are cluttered with too many trees. Another problem is that the wrong species were frequently planted. Evergreens, junk maples, crab apples, ornamentals, and other non-indigenous trees make old courses look more like cemeteries.
For example, I was at CC of Detroit last week. There's an over-abundance of trees at CCD. But more than that, the ugliness created by a broad contrast of species really stood out in my eyes. Conversely, there are a few holes at my home course, Essex in Windsor, Ontario, where the junk trees have been removed, leaving native oaks to dominate. Those holes look so majestic, uncluttered, and generally healthy in comparison.