These dungeons clearly aren't meant to be some hugely game changing thing. It literally was created simply to add content and something more to do other than grind. The SP is presumptuously on par with that you can get in competitive linked levequests.

Capping dungeons is a miserable tactic that clearly did NOT work in XI. Why? Because you couldn't get anything done in XI. Capping dungeons made it so no new players could progress through the game without begging or even paying other players to come with you.

Capping dungeons or even story mode missions prevents players from experiencing content and continuing to play the game. Will these dungeons eventually get replaced or go unused? Probably, but you could say that with any content in any MMO. The fact of the matter is, when they do go unused what happens to the players that want to experience them or get past the requirements of beating the dungeon to unlock a future one?

One of the most important things SE should have learned from XI is that capping things is a bad idea and prevents future players from staying.