This is a sad retcon of the Other World. As first presented, it's a mythic of monsters and heroes, where new wars constantly break out over sometimes trivial things.
One of the things I liked about Dragon Maid was the Nietzschean will to power of the dragons, something the first season anime leaned into, even adding a line to the beach episode, "Ah, look at all these people gathered to enjoy the beach... Doesn't it make you want to swoop in and mow them all down?" Or "Ishukan Communication," its lyrics:
Why are these rules so restricting?
They make my chest feel so tight.
How inferior and foolish these values are!
I've decided they're no good!
I've no need for these morals!
Ah, I want to burn them all down!
It wasn't more right or more wrong than our world, it was just different.