This is a little bit nitpicky; you're focusing on one word when you (and most everyone, I'd wager) know exactly what the OP is talking about. The content flow in FFXIV *is* very stale and predictable, because the core aspects of each version update are known in advance.
Anyway, as others have said, including myself, the primary issue is twofold: stale content flow, and artificially limited content at the 'end-game' edges of FFXIV. It's these two factors working in conjunction that are so harmful.
For instance, Duty Roulette: Expert invariably has only two dungeons in it at any given time. An update comes out, two new dungeons are added, but at the end of the day, Expert still has only two dungeons available. That's terrible design; it's not just that two dungeons is relatively bland from a content perspective, it's that they also replace previous content completely in the Roulette.
Primals and Raids (both Alliance and otherwise) work in the same fashion. Because of the continuous iLevel creep, the problem of receiving only a small-ish chunk of content each update is compounded by the fact that it immediately renders the previous version irrelevant. So, people who are grinding for gear basically feel a 'hamster wheel' effect; the maps are different, but the grind doesn't vary in any meaningful way.
There doesn't need to be some large wholesale change in the core patch content. There needs to be a few more 'experimental' types of content than we've seen, and they need to be better thought-out than Hunts or Diadem, but by and large, the changes can be relatively incremental. The catch is, SE *must* slow down the rate of content expiration. The end-game grind right now, in this period between 3.5 and Stormblood, should involve every bit of Alexander. Farming / participating in Alliance Raids should involve each of the three available Raids (Void Ark, Mhach, Dun Scaith), rather than just the most recent one. Expert Roulettes and Level 60 Roulettes should be one and the same, so that people still have a bit of variety when grinding Tomes.
I don't care how they do it. There are options for keeping content relevant; side-grade gear, upgrade gear with required items dropping in previous dungeons or raids, probably other ideas, too. But it needs to be done. It's important to a lot of people, regardless of any individual's specific feelings. Any excuses made for the current system are tantamount to sticking your head in the sand.