This is a long article with a lot of items to discuss, but my take is that its "easy" to "brainwash" people because a lot of what's being offered is actually good, but, of course, used cynically and for social control. The Hare Krishna kid didn't know it before, but he now realizes that meditation helps with his social anxiety. Except now, he's in bed with the Krishna's, instead of finding a personal and secular path…
This fits well with his point that as the times change so do the "cults", as the leaders are just con-men praying on people's loneliness and insecurities.
Anyone would be skeptical of a group of people it had all of the earmarks of a cult from the 60's (robes, rituals, communes, dirty hippies, etc.), but what could possibly be more innocuous and "normal" than a group of attractive women wearing yoga pants indulging in the latest diet fad? So what if there if there is a side helping of brainwashing, you're part of a hip new community!