I think your comment is what's "wrong" with the world. You are applying your western values onto a completely foreign culture. Modern medicine? I'm sure after having survived for that long, they are perfectly capable of taking care of themselves. You want to give them jeans and t-shirts too? Maybe the gift of starbucks?
It's the opposite of a zoo that the op is talking about.
Who cares if their civilization is 65,000 years old or 2,000 years old. They have clearly indicated, as a matter of their own free will, that they are not interested in our big ships, little ships, helicopters, cameras, or anything else they've seen of us. So why do WE have some moral authority or responsibility to show them "what they're missing". Your perspective is relative to your own life. In order to "inform" them of their options we'd have to basically invade their space, go against their free will, and would probably extinguish most of the population in the process. Once again, as the OP said... LEAVE THEM ALONE!
They're part of the Andamanese people, of which there is data (from the surrounding islands described in the article you read). http://en.wikipedia.org/wiki/Andamanese
Also, if it's no one's call to determine whether they leave or not, why would it be anyone's call to unilaterally interject into their society? Besides, I figure if some of those people do really want to leave, they can set up camp near the beach/wreck unarmed (probably at the risk of civil war, but hey, it's their call). One of us will probably notice eventually.
And to build on that, if you really want to give them free choice, rather than going into their island to forcibly "enlighten" them, build them a removed, but easily reachable dock in the reef/wreck or something like that. From there you can do all sorts of things. A mini library, a vessel, etc. Though I wonder if any of them have even bothered to explore the extant wreck.
It's the opposite of a zoo that the op is talking about.