The reason chefs order meat medium rare is because that is legitimately the perfect temperature where the meat is cooked through thoroughly enough yet won't be dry. Medium Rare tends to be extremely juicy and tender, which is exactly what you want out of a steak.
I'm okay with people who want it a little more or less red, that's fine. People who choose well done are clearly completely stupid, though. You might as well just take a dump on your plate and eat that, because it'll have more flavour than the meat you want the chef to destroy for you. richardheads.