I know they all hate Orson Scott Card, but they'd really hate him if they knew about Pastwatch: The Redemption of Christopher Columbus. In that book, time travellers go back to prevent the conquest of the Native Americans, only to discover that earlier time travellers caused it to prevent Europe from being conquered and subjected to a regime of human sacrifice.
I know they all hate Orson Scott Card, but they'd really hate him if they knew about Pastwatch: The Redemption of Christopher Columbus. In that book, time travellers go back to prevent the conquest of the Native Americans, only to discover that earlier time travellers caused it to prevent Europe from being conquered and subjected to a regime of human sacrifice.