1. The Prime Directive actually goes against your argument here. If you're invoking the PD then the Son'a should be able to handle the Baku themselves 2. As I and others have repeatedly pointed out, there is ZERO on-screen evidence that the Son'a were going to betray the Federation. This keeps getting brought up, and let's just resolve it right here: what evidence from the movie do you have on this? The Son'a spent MONTHS following the Federation's lead on this, going along with a plan that they didn't even like, just to be cooperative. They ONLY turned against the Federation after Picard sabotaged the plan. Enough with the "the son'a were going to betray them!" nonsense. It's the SON'A WHO WERE BETRAYED! 3. The Baku had been living on that planet for three centuries, never telling anyone else what they'd found. The perfectly logical conclusion from this is that they didn't care at all to bring this revolutionary resource to the rest of the galaxy, therefore it makes perfect sense to conclude that they are utterly selfish and self-centered.