Lots of thought-provoking stuff in this thread, just adding a little pigweed to the mulligan stew:
Non-interference with catastrophic events might suggest that the Federation understands things about progress or sociology that we currently do not. Consider the criteria for First Contact (as in the eponymous episode): you make first contact only when a society reaches warp capability - and is about to learn the galactic truth without anyone else's help. Consider it was the Vulcans who first introduced Humans to this concept, establishing it as a "proven" policy prior to Earth's own involvement in galactic events. Consider planets such as Kespritt, Malcor III, Bajor, and no doubt others, who were denied Federation membership; and their reasoning for this denial.
(I'm also a bit reluctant to use real-world examples, as the fictional universe simply glosses over salient issues like economic systems, etc. So ultimately, it's just a story for the purpose of telling in forty minutes or so - no time for nuances, we need big bad Klingons - boom done).
It seems to me that in order to become a functional member of this Federation, your planet has to reach a state of unification; in order to permit the Fed not to have to come in and get enmired in your internal politics, but to be ethically capable of interaction on a meta-political (et al) level.
That is the Federation's contact point. Prior to this state, there is simply nothing for the Fed to lawfully engage. No contact points. This is not philosophically but simply legally (and of course the universe is messier than that). Saving planets from catastrophe means that the Fed is now dealing with societies in a co-dependent relationship; providing crutches to cultures who, for whatever reason, are not in fact capable of unification and the technological advancement that creates, symbolized by a warp-capable galactic perspective. It's not denying the validity of non-spacefaring societies - in fact it is respecting them. And respecting your own legal limitations, which concern themselves with spacefaring cooperation of willing planets only.
Advanced civilizations are created through the successful navigation of their own crises of survival. If they are too busy bickering to build an asteroid deflector - that is their own myopia. They would have added nothing beyond burden and ethical quagmire to the superordinate society of the Federation - a society built on principles of liberty, cultural egalitarianism, and big-ass ray guns that could eat rival nations and whole planets for breakfast.
For example - Bajor chose to remain a society enlightened in arts and philosophy and religion - and do little for military defense. When Cardassia swooped in - Bajor was victimized, certainly - but they were also victimized by their own pacifistic ideology, which had obstinately overlooked the reality of the snake coiled beside their picnic blanket. (Now they needed their otherworldly philosophy more than ever because that is all they had left).
The universe is designed so that people die.
The Federation is not responsible for that outcome. But membership to the Federation - is earned. Not because it is better; but because its responses are limited by a model of specific legal ethics that do not empower starships with carte blanche authority to play Monopoly: Evolution Edition™. To create dependency societies, welfare states, ideological quagmires, or eugenics experiments.
If a captain wants to rescue a society - that's their choice. But the Federation is by no means ethically responsible for the survival of that society - because it has no legal mechanism for dealing with intraplanetary crises. There's that liberty thing again. You save one society from impending death, and now you can justify a nazi experiment for the very same reason.
It's not a question of right or wrong; it's a matter of legal authorization as a representative of an organized society. You can't act as that representative, using all its cool toys and gadgets, for acts that lie outside its authorized mandate. At that point you have usurped your role and are acting as a rogue element. And you have ruined that society's chances for future membership in the Federation by dint of its intrinsic social dysfunction to solve its own problems.
Now, once you are warp-capable, the Federation will help you deal with other planets and medical crises. But not your own elections or coup d'etats. Your whole planet gets ONE seat at the council. And if you were too busy arguing about sky monsters to invent a way out of your earthquakes - tough noogies. Let your sky monster stories succor you on your way to extinction.
The Federation is not enjoying watching this. It simply has no mechanism for a response. That would alter the fundamental nature of the guiding principles into one of state-centric authority, and be a step closer to actual totalitarianism.
We all make a choice authorizing government access into the personal lives of its citizens. Too much access, there goes liberty. No access, then terror thrives. It is a choice. Both choices will certainly generate outcry.
A captain who violates the Prime Directive is like an officer who strikes another officer, or one who steals a ship for personal errands. They aren't just being gallant - they are effectively resigning. (IRL, sans the Plot Directive).
