Scientology is a bad idea all around.
Nope. Although it would be far less dangerous if that were even vaguely true.
The really big problem with scientology it the simple fact that so much of it actually does work.
Although Hubbard did create some new techniques, and did provide an internally consistant philosophical framework, mostly he collected workable stuff from all over, and re-branded it as his own.
The only reasons scientology hasn't taken over the world is diminishing returns, organizational abuse, and that the upper levels undo the much good the lower levels manage to accomplish.