I'm sorry, but you're wrong.
Picard's actions were often guided by the prime directive, even when dealing with an equally advanced race, like the klingons. When the Klingons were having their own internal civil war, between the faction that Worf's family backed and a less honorable, corrupt Duras faction, the Federation refused to help either side, relying on the prime directive, even though the other faction would have been descidedly less friendly to starfleet, and would likely have allowed the Romulans to invade the Federation, if not helped them. The only role the Federation took in this conflict was to enforce the border, to stop the romulans from supplying the Duras faction.
Also, on numerous other occaisions, the prime directive stopped a federation starship from acting to save a species from annihilation. They just sat up in orbit and watched. You cannot defend that as "protecting" the people involved.
In fact, every defense ever given for the prime directive in the show hinges on the unknown future, that if you give aid to a culture, they might rise to form a conquering empire. It is a way to negate any responsibility for the consequences of your actions. Apparently, Starfleet does not believe that inaction is a type of action.
Ultimately, I feel that the prime directive is a form of moral cowardice, so institutionalized and justified throughout the ages that it is mutually accepted by starship captains.