What is the moral of the story, anyway?
It's certainly not
an argument in favor of total
non-interference, since a) Archer elected to ease the suffering of the Valakians, while at the same time b) dropping a huge hint that there is a cure to be found.
To rip something not completely dissimilar from the headlines in the real world: by barging in militarily, the United States could quickly end fighting in Syria; does that mean that the US should
Presenting the solution of offering only extremely limited aid is an effort to speak to what kinds of solutions people have to live with in the real world, and the degree to which the premises are contrived in-universe is typical of the Star Trek
way in fantasy of setting up dilemmas. "Dear Doctor" is certainly a less contrived episode than, say, "Tuvix".