Moral issues

The 'Show, don't tell' rule is especially pertinent when it comes to immoral acts.

Until a book becomes moving pictures, any moral issue with it doesn't seem to reach national press levels, because it shows these contentious issues to a wider audience.  If you show the act, but don't tell anyone what to think about it, the fact that an author or film-maker hasn't clanged down a big sign saying 'And this is bad' is tantamount to advocation.