I think its what you plan to use or the purpose of the double that decide if you scope it or not. And your own valuations. If you have a more valuable double and want to scope it, you likely put in some extra money to secure that it will be done carefully. Both appearance and function. For myself I want to use, hunt and shoot with my rifles, they are not only for exhibition. It is nothing wrong with not scoping, thats everbodys decision to make. But if you scope it you can be in "both worlds" of hunting