Obvious arguments, that is, arguments that are easily understood by the audience of a film, are made mainly through plot, chronology, dialog, and acting. If a filmmaker is making an argument, he should rely upon these rhetorical tools and through them make the argument as clear as possible.
If Oliver Stone wished to make through this film the claim that the media glorifies violence and makes celebrities out of murderers, there are several things he should have done in this area:
Stone, however, is unsuccessful at most of these tasks.