As a kid, I used to read a lot of L. Ron Hubbard's sci-fi (Battlefield Earth and the Mission Earth series). I actually regret that I gave any money to that man. Scientology's rejection of psychiatry, specifically, makes me want to vomit with rage.
I totally understand and support someone who separates a writer's religious beliefs from their writings, but with Hubbard, I can't do that, because he used the writings to fund the cult he formed, and from what I've read, he did so knowingly scamming people. Not only did he take a lot of people's money, but his views on psychiatry cause people not to seek legitimate treatments.