: "... Starfleet has permitted several civilizations to fall. We have at times allowed the strong and violent to overcome the weak
Beyond we weren't there at the time, or we were powerless to stop it. Starfleet permitted
it to happen. Data is implying that Starfleet was in a position to stop the occurrences, and made the conscious decision not to.
There is a certain harshness to the prime directive.
At it core, it is an inhumane policy, but the the majority of species in the Federation are not Human. In the 24th century, it wasn't simply we won't engage in conquest of the primatives, it goes beyond that to we wouldn't help the primatives in any way, even to stop extinction.
Would Starfleet (hypothetically) have stopped the Vulcan landing upon the Earth in the movie First Contact? True, a small segment of the Human Race had achieved a single warp flight, but the vast majority of Humans alive on Earth were not a "warp drive culture