Those were all unfortunately the reasons I could not side with the other factions, either. At least not without compromising both my, and my first Watcher's, morality. While the RDC may come off as wanting the "best" for the most people, @thelee hit it well in that:
In the end, I believe all the factions truly are only looking out for themselves and their interests - what sets them apart is how much potential there can be for growth, and the betterment of the entire Deadfire as a result of that growth.
I feel the Huana may have the most potential for this growth, with the Principi a close second. VTC cares too much about money, though it is unfortunate the sciences and research of animancy are tied up so intimately with them (my Watcher supported animancy in PoE1, despite the multitude of problems it had). The RDC does not offer much opportunity for change and betterment, at least not outside the scope of Rauataians > everyone. Though all of this is from the viewpoint of someone who did not push many of the faction quests, and who in the end chose no one. Perhaps my opinions of them may be a bit different, had I grown more familiar with the companies through their various tasks and stories. As it was, I think I only pushed the Huana story above any others.
All I know is I really did not like the utter chaos that descends on the Deadfire if you choose no one to help. Huana are no more perfect than the others, but I suppose in the end - it comes down to how much potential one sees in a faction, and which faction most closely aligns or garners the empathy of a particular Watcher.