Your serious argument is one of the little valid points raised so far. And I agree, we might not be in a position to help them now. But the statements that even if we could bring them to our society in a humane manner we still shouldn't, because they're clearly fine as they are... That just disgusts me.
More akin to a guy standing on a ledge of a cliff, albeit precarious but doing fine; if you try to help him, he'll probably fall and die fast. He knows this, and he's telling you to stay the he11 away.
That said, I am sympathetic with your basic view. Les Stroud's Beyond Survival was fascinating, but the recurring theme of "and this ancient people is about to die out or lose their culture" struck me as "well, if doing stupid things[1] isn't survivable then maybe those ways should change, and the consequences of sticking to them are natural." The Sentinese however seem to be holding it together pretty well; not advancing, but living on what is otherwise a stereotypical tropical paradise island (food growing on trees, good climate, water), methinks they've achieved some form of comfortable equilibrium and are doing pretty well (I'm sure some here on HN are thinking "I'd like to join them").
Someone mentioned above "your 100 kids will leave the island, move to India, and become call center employees". That vs. where & how they're living now, I'm not so sure "bring[ing] them to our society in a humane manner" really is. Someday it will happen, someday modern life will crash into their ancient and stable culture, someday they will have to deal with new diseases and cell phones and high-speed transport, and "someday" probably isn't very long from now.
"But the kids need to do X and Y and Z!" my wife declares. "They're content and playing nicely with their toys and crayons," I'll reply. "Let them enjoy it a little longer."
[1] - the clincher was a tribe that fishes by dangling bare hooks in the ocean for hours while sitting on poles. I'm amazed that culture lasted so long. Yeah, they need some help.
Some type of hidden observation as in the movie Insurrection might be worthwhile though? Someone should ask the NSA, are they really comfortable with these people NOT being monitored constantly? They could be a terrorist threat?
Or, you know, they could live a life that makes them happy.
I think you're unnecessarily conflating this with another topic entirely.
So "you should still respect her \"NO\"" - How is this relevant? He doesn't expand on why you should do this, so we can't link that logic to the situation and and, all we have is "You'd accept 'no' if you asked someone out, so you should also do so here", with no further reasoning on how the two are similar.
On a more serious note, given some historic evidence how our contact with other tribes ended (pick any tribe, anytime, anywhere) I am both surprised and happy that they exist. I hope they stay the same for as long as possible and may we never learn anything about them.