So how come The Great Hunt can't be unsynced?

[Neophyte]

I mean to be fair it is Monster Hunter. I can't imagine the team at Capcom would have been happy with the idea that you could eventually cheese their contribution to FF14, particularly given the brutally hard nature of the game it was based on. I can pretty well imagine Capcom citing brand integrity or some other excuse when the idea for the cross over was pitched, because there's no other logical reason why this extreme in particular can't be cheesed.

In a few months when Iceborn comes out you'll see MHW players 'unsync' their older challenging content, too.
For example Behemoth extreme in rarity 9 and 10 gear. So I don't see the point.