Ned was directly blocking the door here, collecting fees at the entrance.
It's not that he doesn't want to hide and develop, monopolizing the resources of this Crystal Series universe... but it's simply impossible to hide.
He knows better than anyone that there's no way to enjoy it alone.
Others will eventually discover this entrance.
If they really believed others were blind, that would be foolish.
It would be better to openly start business here; he has made prior arrangements, letting them have a share, at least dragging the surroundings into the water.
To prevent the surroundings from spreading the word and summoning outsiders.
The very worldly-wise Ned, seeing the shocked expressions of the crowd, directly spoke:
"Only Divine Level beings are allowed to enter here, and they must undergo strict control, allowed only to live, trade, and exchange various materials in the cities of this world."
