Grady uses Evergreen marine wood in their boats and I think since about 2000 or so. This is a far superior product than previous years. Some of the most reputable boats on the water like Hatteress use wood. If they built their boats was build like a Carolina Skiff and I own one, or Bayliner and they used wood, then maybe one should be very concerned. If every Grady was rotting out and falling apart then why would their brand be so strong and their resale value be so exceptional in the boating market? The fact is they are not and those that are likely have been neglected to some degree or another or something installed improperly with water intrusion happening.
Wood has been used for thousands of years building boats and if done right it is a good base. For what it is worth, the tallest dam in the eastern US built during WWII, the Fontana Dam here in the Smokies has a red spruce and hemlock grid work skeleton. During the war steel and so forth was in short supply and it was hard to get here, so they used wood to build a dam over 500 high.