I hated the Prime Directive and have always thought it was a stupid rule to enact and full of holes, though it was good for drumming up random stories about primitive races.
I think Picard cited the first contact between the Federation and Klingons as an important reason why the Prime Directive is in effect, supposedly it would have made that contact less disastrous. Archer, even though his show takes place hundreds of years before Picard, seemed to have been born with an innate Prime Directive given how often he cited some random philosophical garbage about meeting new aliens.
Depending on the writer, I suppose, it seems like the PD had conflicting intentions. Is it supposed to protect the Federation or protect the other races? That much was never made explicitly clear. I never bought their given reasons that we didn’t want to accidentally destroy some race, or that the Federation didn’t want to make a race hate us.
In TNG, the Federation stood by several times as natural planetary cataclysms wiped out or nearly wiped out a species. Luckily, Worf’s half brother saved some of them. But that showed me the PD wasn’t about protecting species at all, because anything’s better than annihilation.
Fears of another Klingon War cannot be justified either. The Federation has thousands of member worlds and just as many species. If it was afraid to interfere in another race’s internal affairs, the Fed would be made up of only the original 5 founding races and that’s it. It’s reputation as a futuristic UN, however, belies that. It actively seeks to recruit worlds into it, displace those worlds’ values with it’s own, and make every world into what the Federation considers their own utopian model.
Allegedly, the intent of the PD was so that the Fed wouldn’t interfere in non-space faring worlds, to prove the above incorrect. However, Kirk and crew “fixed” the Nazi world after finding out a Federation cultural observer turned the planet into fascists. Since the PD only applies to Star Fleet personnel and not to Federation citizens, the observer John Gill’s transformation of the planet would seem to render the PD’s rule of non-interference ironclad and Kirk should have just left it as it. But no, he helps them.
Like the wiki says posits, I think the PD is an example of moral cowardice on the Federation’s part. It’s easier to do nothing than do something, better to throw up your hands and say “Sorry, can’t help you” than try to help and screw up. I think it’s a very arrogant idea that the Federation’s enshrined into the law books, and it isn’t even applied very well (why not all Federation citizens instead of just Star Fleet?).
Let’s not forget, the Fed’s encountered it’s own PD from another race, the Organians, who stopped the Federation-Klingon war cold. I would have bet the billions of people who would have died in that conflict were glad some race wasn’t all uptight about it’s moral code and decided to use their powers to help.