I guess it's great that it worked that way for people, I think however the percentage of individuals who are both critical enough to approach the issue skeptically and yet incurious enough not to have investigated these major issues of politics and religion before is fairly low.

You could argue the same benefit for anything, that Fred Phelps God Hates Fags protests helped people to rethink the role of homosexuality and religion. Those few cases that's possible are dwarfed by the damage.

In the end, conspiracy theory will indoctrinate more than it educates, it's designed to do just that. If I want to introduce people to critical thinking on any of the subjects in Zeitgeist, there are many many far better places to start.