its one of my favorite episodes... I really like the scene where archer Transcends conventional morality, and sees the galaxy in a grander perspective, saying "someday my people are going to create sme kind of doctrine that tells us what we can and cant do, should and shouldnt do while were out here, but until one of my people tells me they've drafted that directive I have to remind myself every day, we didnt come out here to play god"
Curing the Valakians, whle it wouldnt neccessarily have signifcantly affected the menks immediate biological evolution (If the Menk were allready evolving in this direction)
Would have kept the menk from ever realizing their own true potential.
I think Phloxes decision was a valid one.