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.