If you were to destroy the fundamental basis of knowledge of these said people, what would you offer as a replacement? People find comfort and security in their religion; for the followers of the tenets, the religion offers them a place to soothe their souls and ease their fears. For the followers, it offers them a way to understand and make sense of the unknown.
Rightfully, we should correct mistakes, and expose hoaxes in absolute terms, such as when we discover fraudulent practices behind people claiming to have discovered cold fusion. But in this case, we are dealing with people's deepest feelings and emotions; indeed, for some it could be their sole basis for living.
How can we rightfully take that away without offering something in return?