Metadata isn't synonymous with SEO though. Ratings and comments are literally (user posted) metadata.
There will be cases in the system where there are no permissions or privacy settings, but there are rating/comment checkboxes. E.g. a news entry has no permissions (as that's set at the category level), but does allow setting whether you can rate/comment.
There will be cases in the system where there are no permissions or privacy settings, but there are rating/comment checkboxes. E.g. a news entry has no permissions (as that's set at the category level), but does allow setting whether you can rate/comment.