Because accepting any claim and denying the facts leads to religion and the denial of known reality. And history has shown us the destructive and dangerous power of religion.
Because worshiping a child murderer is insane. The fictional God of the bible may have saved Noah but how babies, toddlers, pregnant women and elderly people did he drown? Such evil is not something that should be worshiped.
Because accepting any claim and denying the facts leads to religion and the denial of known reality. And history has shown us the destructive and dangerous power of religion.