People are easily manipulated.
The funny thing is, the "counter culture" groups are just as manipulated as the mainstream. Did you know the 60's revolution started because some guy wrote a book telling kids how their parents were screwing them over? If not for that book, and the capitalizing on it by various lecturers and such, there may have been no hippie movement.
The "conspiracy" part, is I think this is our nature. Masses are made to be exploited. Large groups = herd behavior, to be manipulated by whoever can fill the power vaccume.
And it's telling that in cases of an unfilled vaccume, you get an angry herd. You can see this in third world nations who lack a central authority, or any kind of authority.
So, bottom line, we can't really group think on any rational level. All the thinking, for good or ill, happens from a few people, with the rest blindly following along.
Human resources, indeed.
Oh, and the other part of the conspiracy theory: Western culture is, by and large, being exploited by psychopaths. I'm talking murderous thugs here.. The type who would fit into organized crime.