It all depends on whether this content is worth an entire new game's price.
FFXIV costs roughly $15/month. 3 month cycles per patch means $45 per update to the game. If you are a patient gamer and don't need to buy every game at launch, you can get decent "new" games for $45.

So in essence, when people are complaining that the patch is empty, they are making a comparison of opportunity costs: do I spend $45 playing three months worth of a clearly-gutted patch? Or can I get another game (or two... steam sales/humble bundle) that will last me roughly the same time frame?
What makes this decision even more blaring is the fact that SE has stripped the game of a dungeon for the promise of more content.

Once my subscription is up, I think I'll do what I essentially did the entire 3.X patch series: ride the coat tails of the free log in campaigns. They always seem to occur around the release of new patches, and since I really only care for the MSQ I can log in without needing to pay a sub. And I don't have to partake in the quarterly tome grind, since the second-best/easy-to-get gear fulfills ilvl requirements.

Anyone else who feels there is a lack of content, just remember the opportunity cost above. Is this patch really worth your $45? If not, there's nothing wrong with voting with your wallet.