From class/job adjustments to stat adjustments on normal enemies, bosses, and player characters, the game no longer is fun to play for people who got into the game before Stormblood launched(which is kinda debatable based on other variables...) because of things being to easy to do or too complicated to figure out because of how much RNG that's related to the class/job(AST and MCH are notorious for this and DRK to an extent but the added RNG made 1 stat actually worth investing in for DRK)

Generating enmity/aggro wasn't really that hard to do before, it's just 1 person has to go get themselves by something that shouldn't have killed if they attacked the same target as the tank(or everyone but the tank because they thought AoE spamming because they could was a great idea except for when it resulted in a wipe)

In a game where only DPS matters(which is how RPGs generally focus on first for battle encounters) but if people don't care about group effort then just make EVERYTHING DOABLE SOLO WITH NO EFFORT ON THE PLAYERS PART.

Because clearly that worked for lot of other games that did the same thing right(even though they were originally made with group content first)