Re: Nibiru
So yes, the proper choice would have been to let nuSpock die there and keep the Abramsprise under water, because that way the culture would have been saved without a GOD coming down to them saving them.
ANY visible intervention is bad intervention. You cannot foresee the consequences.
You're conflating two very different issues. I don't think anyone is defending the idea of intentionally publicly interfering with a culture's development and imposing yourself or your belief system/values on them. Secrecy should be maintained at all costs unless it is impossible to do so. They're simply defending the idea that saving a species from extinction is more important than preserving their developmental isolation at all costs, especially when they won't have any more development if you do nothing.
The OP is saying it would be better to let a species die than to interfere to save them at all, even if you can save them in secret without exposing yourself. Bringing up evangelizing and colonization is a misrepresentation of people's arguments against the OP's comment, since no one is defending those things.
Now, obviously, raising the Enterprise from the water and exposing it to the natives to save Spock from the volcano is taking things further and violating the other less morally bankrupt non-interference clauses of the Prime Directive, but that's not what the OP was talking about in his final paragraph. I think you can make a perfectly rational argument (and indeed, Spock does exactly that) that sacrificing a single crew member who voluntarily chose to risk his life as a member of Starfleet and on this mission specifically in order to prevent the species being exposed to culturally contaminating advanced technology is a worthy cause.
But if we sent out a distress call, and they'd react to it by blowing the asteroid up, that would be nice.
How is that not playing God by saying that species who have developed radio communications with enough power to reach deep space are more valuable and worthy of saving than species who have not?
If it all hinges on the species giving consent to be saved for you, then I'm sure there are ways of posing a hypothetical scenario about intervention to stop their demise to the leaders of the species in question without revealing too much information about who and what you are.
What if the species later goes on to do evil like Borg or the Vadwar. You never know how they will develop. That's why they try not to interfere.
And what if they go on to eventually develop a method of saving the galaxy from the Borg or another species/event? What if they develop some beneficial technology or are amazingly successful peacemakers who end millennia of conflict among other species? You're absolutely right that there's no way to know how they will develop, but that's no excuse to only assume the negative.
Also, speaking of the Borg, they serve as a sort of cleaning crew for the galaxy. Every time a species or culture becomes too powerful or advanced, the Borg come in and assimilate or destroy them and essentially sweep them out of the way, thus allowing countless other less developed species to rise in their place where they previously might have been marginalized in their shadow or conquered by them. Now, as long as the Borg don't come to dominate the galaxy all by themselves, they might actually often serve a beneficial role for the development of younger species from time to time, much the same way a forest fire burns away old trees and brush but also enriches the soil and makes way for new trees and shrubs to grow. Now obviously, the older species aren't going to see it this way as they're assimilated and their demise is no less tragic, but it's all a matter of perspective.
Anyway, my point is, like you said, there's no way to predict the future outcome of saving a species from extinction. But where you think that means you should not interfere at all, I think the moral thing to do in the here and now, which is the only thing you can see and manipulate clearly, is to save a species from extinction if you have the capability to do so. Anything else is callous.
