You are the first person ever to ask for that feature. When it comes to adding new options, our rule of thumb is we add it if 80% of our users would find it useful.
The whole point of being able to copy lists is so you can configure different "views" onto the same data. The menu setting overrides are just a convenience for overriding some of the most common settings on a per-menu basis, like pre-filters, which elements you display, etc. For "fine grain" stuff like hiding or showing specific buttons or menus, list copying is what you need.
Just to be clear, a copy of a list still sits on top of the same underlying table, operating on the same data. It just gives you a separate collection of list / form / group(s) / elements that you can configure differently.
-- hugh