That the Prime Directive only applies to pre-warp civilizations.

You’re not wrong, but man the Prime Directive would make a whole lot more sense if it did. The wrong but commonly understood version of the PD that is intended to prevent cultural contamination is clear and simple. Given its status as the literal top rule, the actual PD—a generalized non-interventionism/pro-isolationism dictum—is oddly complex, vague, and lacks a focused objective.

All of this could be avoided if they’d just rename it to the Mind Your Own Business Directive.