https://old.reddit.com/r/changelog/comments/2a32sq/experimen...
Apparently, there were some subreddits that got bombarded with unwanted comments which prompted the new feature.
It's located on a page that you only visit once to set up the subreddit, or to make large subreddit changes. (On old reddit, not sure about new reddit)
To Reddit's credit, they have been adding new features over the years to help separate communities and ensure they are somewhat able to maintain their culture.
E.g. Crowd Control which limits the posting / commenting abilities of individual users based on their history or other heuristics.
Aren't you of the opinion this could be misused?
If admins wanted to disappear a viewpoint, it would be a lot easier to just autosuspend the accounts, or shadowban without a trace.