No no, you misunderstood me. My request was more motivated from an attack point-of-view. So, imagine a hacker successfully gets inside the admin interface. I could add some protection by disallowing file edits and plugin installations/updates so that he cannot do much damage. But this is quite inconvenient because whenever I want to do a plugin or wordpress update I would have to release the lock by flipping DISALLOW_FILE_MODS.