Public service announcements are usually created by advertising agencies full of people who know how to sell products and brand companies but generally know very little about education.
These ad agencies know how to beat a message or song into our brains, how to create imagery and scenarios that stick with viewers, and how to send a message to the masses.
But they don't really know much about restraint, since over-the-top ads help them sell products, so maybe hiring them to make PSAs isn't such a good idea after all...
See 7 Safety PSAs (That Were Clearly Made By Serial Killers) here (contains NSFW language)