Well, I agree. The planet belonged to Ba'ku and the Federation had no right to claim it. There could have been only one Ba'ku there and it still would have been wrong to take the planet. Are people really saying that the Federation should go around conquering planets for natural resources?
Only in extremis. I'd say there would be one justification for any amount of thievery--species survival. It's why I can't find it in my heart to condemn the Vidians, ghoulish as they are sometimes (that the first victim of theirs we ever see is Neelix does, I admit, also land me bang on their side at first--I saw s01e04 of Voy after I'd seen most of the series, so had plenty of time to become comfortable with the idea of
Neelix being chop shopped). Survival trumps anything else--no "principle," which is, after all, just an arbitrary social code, should take a front seat to survival of a species. If you stop existing as a species, the rest means nothing.
But none of that is at stake here, so I completely agree with you: ownership trumps any perceived "need" that is not species survival. There is only one justification for the kind of banditry being discussed here. If we have to sink to that level, there needs to be the very best of reasons, because however arbitrary the decision not to simply take resources from others is, The Federation would know what they had collectively done--eventually the truth would get out, it's too big to keep a secret--and they would know that they are debased because of it and so would BE debased. In nearly the worst possible way, by current Federation standards, and, let's face it, human standards. Hello Terran Empire.
But we're not talking about resources that a readily available all over the galaxy, like dilithium. We're talking about something that can help the health of billions and is located in one area. Which is just in an entirely different ballpark.
We have six hundred people who are usurping the resources of an entire planet for themselves. That, to me, is simply wrong. I don't really care if they stumbled upon. It is also obvious that they aren't interested in sharing the planet with those with differing opinions on how life should be lived or else they wouldn't have kicked the S'ona off the planet to begin with. And it really is a numbers game. With a planet with hundreds of thousands or even millions, the logistics simply don't work out to move them.
Sucks to be them.
Once you do this, you really are no better than the Klingon Empire or Romulans or Cardassians. Or, as mentioned above, Terran Empire. Halkans, Bak'u--all the same. Their stuff, us taking it--or not.
Wouldn't matter if ONE person held this resource. It is theirs. Their property. Period. Only survival as a species would justify taking it by force.
Also: who makes this decision? It's pretty momentous. The Federation would be setting itself on the path of every other militaristic, might-makes-right empire, instead of continuing as one of the truly most enlightened political units portrayed in Trek, warts and all; might not the Federation Council, at least, reasonably need to be consulted? So that the trillions of Federation citizens have some voice in such a significant sea change of policy?