QUOTE (Neraph @ Nov 25 2012, 04:35 PM)

This mindset actually makes me angry. Who are they to determine what is and is not needed in this world anymore? The loss of knowledge is always a dark stain on humanity's history. They essentially try to romanticize their own selfish outlook on the world, and the world actually becomes a worse place for it. It's entirely possible that there's a ninja technique that would dramatically change the way physical therapy or rehabilitation is done, or a swordmaking technique that would simply and change the method by which surgical scalpels or industrial equipment is manufactured. People like that do not know how their knowledge could impact the world, and declaring their art or trade "worthless" because it's "not needed anymore" is not only a selfish statement, but a close-minded and ignorant one.
Note how the first quoted Grandmaster said that he first believed he was being taught to be a
thief. There may be ethical concerns involved as well as a belief in obsolescence. This is, after all, the art of the ninja we're talking about - the arts of going about unseen and of murdering people rather horribly.
The only "legitimate" consumers of those techniques may be governments, and he may not wish to see his clan's techniques turned into those of the JSDF and whatever spying agencies Japan has; he may believe (Rightly or wrongly,) that the legitimate consumers of his teachings are already in possession of superior training (they definitely have superior technology,) and his techniques can only serve to empower those who should not be empowered - freelance spies and assassins, which he may believe the world no longer has any need for and which will be poorer off for having.
On the other hand, you're not wholly wrong in that looking into ancient techniques can yield startlingly effective modern benefits. For instance, in the notoriously earthquake prone country of Japan, someone eventually noticed that while old houses and the like tended to topple quite easily, surprisingly-ancient Shinto shrines tended to stay standing; they investigated this and found out that those enormously tall pagodas had been constructed with a massive tree trunk suspended on the inside, floating freely inside the structure save for being affixed at the bottom. I don't pretend to recall, much less be able to explain, the physics behind it, but it sure as hell works, and was easily adapted by putting huge, free-floating steel pillars inside modern skyscrapers. Also, I believe Japanese swordmaking techniques has also already been applied to scalpel technology. It's unlikely that any further improvements will come from secrets in the hands of the Ninja clans, as they were not really the katana-owning badass honorless sneaky samurai that Western media makes them out to be (the word for that is
Ronin,) but were, indeed, poor. See also: the Grandmaster of the clan works a day job as an engineer.
The times are indeed a-changing, and there may indeed be no place for the Ninja in the 21st century. I'd say that living Ninja Grandmasters are probably in a better position to state so with authority than you or I.
Though, I do kind of hope that he does meet with medical professionals to go over those ancient medicines and poisons he mentioned. Those might legitimately be useful to modern society, and it's entirely possible they've escaped medical knowledge until now, especially if the Clan had a vested interest in suppressing such knowledge getting out even as late as fifty or a hundred years ago.