As of Stormblood patch 4.1, FFXIV's endgame cycle is generally 4 Savage fights followed by an Ultimate fight. The four savage fights last us 3 months, and the 1 Ultimate fight lasts 3 months. The goal of Savage progression is to gear up to be ready for Ultimate; this means 8 weeks as a near minimum for all the gear necessary to tackle it. Not everyone is going to attempt Ultimate due to its sheer difficulty, however it is a fight that on its own will last people 3 months easily.

So with Ultimate, the endgame in my opinion has a nice round cycle of "3 months to gear, 3 months to win the challenge, repeat." I can understand people who don't do Ultimate not agreeing, because then the entire 6 month cycle kind of loses its point and you're left with 3 months of nothing.