Unless i get banned again but.
Its good because it challenges patience, patience is the keyrole to be ultimate powerful. Its good motivation because jobs are different, have different abillities. It challenges the strong minded, how much are you willing to put into this game? I actually replayed job grinding up TWICE because i forgot bestiary. Now i have 5 levels left to level 99, i got all chests and i have only iron giant left to beat then i will have all bestiary and iron giant achievement on steam, so i essentially job grinded all jobs to level 99 twice due to it.
Its essentially a good game because the reward is patience, and once you get to that level you become very powerful. Thats why its very good.