Choosing to let millions of people die on the off chance that some other people might develop intelligence in a few thousand years has nothing to do with what it means to travel through space. That excuse is especially poor, since the idea came from a man who was very familiar with space travel and interacting with other species.
I guess I meant "space-faring" in terms of "Star Trek
space-faring" (where the ships encounter aliens and problems on a weekly basis). In the other series, this stuff is old hat. They would encounter a problem like this and would resolve the issue where everyone wins out. "Dear Doctor" didn't and had the characters make a controversial and potentially wrong decision. At least, that is what I took away from the episode.
Except there was no good reason why everyone wouldn't have won if Phlox just gave the cure to the Valakians? I don't see how this episode presents a good dilemma, how is the Menk's supposed future evolutionary leap a good trade off for the entire Valakian race dying off? A child would make the right decision here, so Phlox and Archer failing to do so, doesn't come off as a bad choice due inexperience, at best they made this choice because they were incompetent and at worst they made this choice because they were malicious.