T'Girl, it's common in SciFi when you have a civiliation that has chosen to live Low Tech, they don't want neighbors with anything but low Tech
They being the Baku I presume? Again a Federation planet, why would the Baku have any say in the matter?
If the decision of the Federation Council was made to leave the particles in place, bringing the patients to the medicine, instead of the medicine to the patients, this means in addition to the hospital I wrote of, there would be entire communities.
The Admiral spoke of the particles helping billions, that would imply the necessary of massive infrastructure being introduced to the surface of the planet. Not just little villages, but lots of large cities like modern day Los Angeles, in multiple places across the planet.
After becoming well again, not everyone is going to want to return home, they will settle there permanently. I would imagine it becoming a popular retirement location.
... that only Dougherty's bringing the Federation in ...
While it was never broached in the movie directly, the feeling I get is that the Sona themselves first approached the Federation Council and that Admiral Dougherty would have been assigned to the operation at some later date.