Thank you, Square, for listening to the majority.

[Doozer]

So was it really world visit to blame?

Yes. Because it's the world visit system that allowed people from other worlds to clog up the instance. What lets people from other worlds do that? Literally only world visit. Only world visit lets people from other worlds fill up an instance. If you take out world visit, people from other worlds can't do that. Therefore, duh.