Scientology and the history of quackery

[Major Nikon]

Back in the 50's L. Ron Hubbard was hawking various forms of quackery as a cure for everything from radiation sickness to clinical depression. Not surprisingly the FDA took enforcement action against his quackery. Then something interesting happened. Hubbard starting calling his therapy a religion, eventually even securing federal recognition as such. Now the FDA is powerless to go after their quackery as it is protected activity under the First Amendment.

So why is it any different for other religions? If people are perfectly willing to accept begging favor from a poltergeist has healing properties for their supernatural essence, why is it so difficult to accept dianazene pills and ohm meter therapy would have the same effect?

Follow up question:

To what point are we supposed to accept or reject the sincerely held beliefs of Scientologists? Is calling their methods the work of charlatans and hucksters really any different than saying the same thing about anyone else who uses "faith" to efficiently separate believers from their money?