PSAs clearly align with archetypes of good and evil. Expressing anger through actions? Evil. George Zimmerman killing an unarmed teenager? Not evil.
drunk driving
It’s the Lizzie Bordenification of drunk driving -- even though we do it, we couldn’t possibly do it. At least as far as most public campaigns are concerned.
disability rights
I think the concept of riding a bike is as metaphoric as you can get here. It shows that the idea of putting one foot in front of the other and asserting oneself in order to move forward is universal -- not just applying to the momentum of a thing on wheels.