That kind of knowledge was troublesome for two reasons. The first one meant that the more time passed, the more the enemies will have time and resources to create their perfect worlds that were similar to their original territories. The minotaur was able to create a dungeon created to his own labyrinth, so one could imagine what could happen if someone like Odin had time to create something like Valhalla.
The second issue would be the fact that the world would change so much and it was already happening and people might feel like it is a waste of time to try to fight back. That wasn't a real problem for Jason, but for most would.
"You have a bunch of fragments, you can create your own territory and use the others to make it expand faster by creating dungeons close to each other," Loid said. "As you can guess, food won't be a problem if you can shape the surroundings as you see fit."