I'm with sfdebris (he has a 15-minute video on the topic on his site that's worth checking out) when it comes to the Prime Directive: it seems to me to be more moral, and make more sense, as it's applied in TOS. (Or, at least, as it's
supposed to be applied in TOS, Kirk being fairly notorious for treating it as the Prime Suggestion!)
In TOS, it seems fairly clear that it's intended as a barrier to cultural imperialism; i.e., our heroes can't/shouldn't alter a culture to make them more like us, or more like what we find acceptable. In TNG and the other sequel series, it's presented as prohibiting
any interference, no matter how covert or benign, and no matter the nature of the situation. That's harder to defend.
Where's the logic of a code that lets a species go extinct because interfering would alter their natural course of evolution? Clearly, an ideal that values noninterference, for the sake of not affecting their natural evolution, would want them to HAVE some evolution, no?
in the case of by not intervening letting a species die out (such as was the dilemma in Homeward) in my opinion there simply is no such flip side. Any damage that would result to their culture is preferable to letting them simply die out, in my opinion.
If they're all dead, preserving their culture is a moot point.
Protecting themselves is part of it, but I always get the impression the two biggest factors in TNG's misinterpretation of the PD are 'Next Hitler anxiety' and worry about interfering in the grand plan of the universe.
Misinterpretation indeed. The "next Hitler anxiety" is bizarre. Real-world analogy: there's a car accident on Main Street, and an EMT rescues a child from the wreckage. The child grows up to be a mass shooter. Does anyone --
should anyone -- blame that emergency worker for rescuing the kid in the first place? No. They might say, too bad the kid was rescued, but they wouldn't blame the EMT, because that's not a consequence the EMT could reasonably be expected to foresee. OTOH, if at that same accident the EMT refused to rescue the child because the kid
might become a mass shooter, would we be okay with that? Of course not.
The "grand plan of the universe" is even more easily refuted. As Troi said in "Pen Pals," if there
is a cosmic plan (which strikes me as a bizarre concept for a secular society anyhow), how do our heroes know that they're not part of it? I'm fond of a joke where a man, trapped in/on his house because of a flood, turns down rescue from, in turn, a rowboat, a motorboat, and a helicopter. He says God will save him. When he drowns and dies, he confronts God in heaven, demanding, "Why didn't you save me?" Says God, "I sent you a rowboat, a motorboat, and a helicopter!"
Suppose one of the Borg invasions (or the Dominion) had succeeded, and Picard had asked a more advanced species for help only to hear that the federation is too primitive for their prime directive to interfere, what would he have thought of that?
Serve him right, IMO.