There are significant amounts of truth, to that statement.
Marlin Marynick said himself (paraphrasing):
"I was a half-assed nothing who hardly knew how to read or write, never read a book all the way through in my life, didn’t know anything except jails, couldn’t hold on to my wives, was a lousy pimp, got caught every time I stole, wasn’t a good enough musician to hit the market, didn’t know what to do with money even if I had it and resented every aspect of family life. But a week after Sadie’s story, I was a charismatic cult leader with a family, a genius who could program people into doing whatever I asked of them".
Lynyrd Replies Further:
I believe "the times"... and "very unique social circumstances" allowed Manson... (an otherwise small-time criminal)... to "blossom" into something much more.
Given different circumstances (say 2011, in S. Dakota)... it's likely Manson (as Tom suggests), would have been an unknown con-man... in-and-out of prison (mostly in), for lesser crimes. Essentaially... a bum.
Circumstances came together... much like planets aligning (in the 60's)... and Manson was given "free reign". Things deteriorated.
There's an old proverb which applies here, which I quote often:
"Absolute power, corrupts absolutely". It's my opinion... that the "group experience" corrupted Manson... every bit as much... as it corrupted the others.
For No Apparent Reason. "I'm gonna Barbucue your ASS in Molasses"! AHahahaha