Movies
Who else is going to change the world, Marty? Greenpeace?
— Cosmo • Sneakers

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
A rhetorical jab: if not us, then who will change the world? Naming a well-known activist group as the alternative is dismissive and sarcastic. It mixes grand ambition with a sneer at anyone who might compete for the job.
Context reviewed