The reason why there are various limitations is due to the problems with instance occupation and content occupation. I have every intention of wanting to avoid making people wait in line for instances that are occupied by parties that do not meet the number of members or rank to be able to clear a dungeon.
No one is frustrated with this part? Really? Waiting in line to enter dungeons shouldn't be happening anymore these days...
Limitations? What there aren't enough servers? No monies for servers? These dungeons don't have to run on the same servers as the "World" servers. They're instances...