Imagine crewing a huge ocean going sail vessel and sailing for who knows how long just to drop a kid off at an island. Where for hundreds of years the kids have just been killed by the local wildlife.
I mean... If you're just going to drop kids off and let them get killed, why sail out in the middle of the fucking ocean to do it...? Of course, the better option would be... not to just kill innocent kids because a mark on their body that they had no control over appeared... But if you WERE going to an evil asshole, it doesn't make much sense to be this much of a convoluted asshole about your murders.