This is because the one-liner is actually (sorry SSC) a valid logical template, relying on assumptions about rule of law to draw a deductive inference. We can s

This is because the one-liner is actually (sorry SSC) a valid logical template, relying on assumptions about rule of law to draw a deductive inference. We can see the template itself: "When X is illegal to possess under some jurisdiction's law, then the residents of that jurisdiction will be criminalized by their possession of X, and thus the only possessors of X in the jurisdiction will be criminals." SSC probably doesn't like this one because it's definitional. People like to use "criminal" is a qualitative label for people who they feel have broken the law, but it is in fact definable as a quantitative label for people who have committed acts which are unacceptable as a fact of law.