The Overlord wrote:
It is bad science to suggest that nature has a plan or species evolve into extinction, neither of those things are even remotely true.
It is indeed yet Phlox does not make such suggestions.
He merely compares the Valakians and the Menk with homo sapiens and the Neanderthals and says that giving the latter an advantage is wrong.
It is a question of the time horizon. Is this an ordinary sickness we are treating or are we giving one of two sentient species a serious long-term advantage?
I think the latter is true as we do not talk about an external issue like a plague but about collapsing chromosomes.
If they gave them the cure they would have to counterbalance this via making them commit to treating the Menk better unless you wanna claim that biological issues are more important than social ones.
To use your example, providing sick nazis or slaveowners with medicine while not caring about the people they subjugated would obviously not merely be wrong but a crime of vast proportions.
Or to use again my animal rights comparison, the Valakian mistreatment of the Menk is as natural to them as our treatment of animals as they have done it for tens of thousands of years. The idea of equal rights is totally alien to them, you'd have to literally force your ethics upon them.
So the Enterprise crew would have to cure a genetic breakdown and redesign the social fabric of two species. Sounds awfully close to playing God to me.