FFXIV: ARR was designed to be a casual themepark mmo, you come, ride for a bit till you start to burn out, and take a break (yoshi even prefers people to take breaks) massive burnout sucks it makes you not want to play any more ever, it happened to overwatch too, where a large base left due to massive burnout.

They add hardcore stuff occasionally for those who want a challenge, but they wont base a whole job around it.
They set the SB jobs at 50 so people could easily grind the levels for the new content, unlike all the backlash they got in HW for their jobs starting at 30.
because once again, this is like a ride, you come, you experience all the rides, and when you have your fill, you leave, and they rather you leave happy rather than angry.