People
Actually, I’m probably the only person who’s qualified to let you know exactly what a jerk you are. But that’s okay right? Because if everyone thinks you’re a jerk, no one will bother getting too close.
— Jodi Picoult · My Sister's Keeper

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker claims special authority to criticize the listener, then suggests that an unpleasant reputation may serve a purpose. If people keep their distance, closeness can be avoided. The turn changes an insult into a pointed observation about how hostility might function as protection.
Context reviewed