Given the moral ambiguity of the Baku it's probably for the best that the Son'a aren't played more ambiguous than they are.
The ambiguities within the film are it's prime attribute. The Sona are evil, but it is they who will bring the health benefits of the rings to the common man in the federation. The beautiful Baku are the ones blocking this process.
Picard's position seemingly is more based upon his personal admiration with the Baku lifestyle, than any legal or moral standpoint.
Even at the film very end, we hear that the federation council ordered a review, but we never find out the review's outcome.