Every job in the game is saddled with abilities like this that are situational and don't necessarily boost your DPS, your mitigation, do your dishes and make pancakes.

DRG: Piercing Talon - the most mobile job in the game, 3 gap closers, and yet it has this crappy ranged ability that does awful damage for an insane TP cost, BUT if all your jumps are on CD and you have to leave the boss for an extended period, its useable.
PLD: Shield Bash - nothing need stunning? then its useless. Tempered Will - no knockbacks? useless.
DRK: Dark Mind - no magic damage? useless. Sole Survivor - no adds? useless. And then there's Dark Passenger.
SMN: Tri-bind!
BLM: Scathe... eh... if you gotta move for a long time and have no procs/swiftcast... maybe?
WAR: Shake it Off!
...And these are just the jobs that I've played at 60-70.

Idk where people get this entitled mindset that every last one of their abilities must have multiple effects and never ever be situational or make you think about how you can make use of it. Everything needn't have 3 different additional effects, a 4 paragraph tooltip and be completely idiot-proof and benefit you no matter what the situation.

Shake it off is pretty bad, yeah, but the degree of RAGE over this ability merely existing is so petulant and silly when every job in the game as abilties that aren't particularly useful in high-end content or are very situational, and Shake it Off getting added to a job that frankly didn't need much more over what it already had, to me, doesn't warrant a chorus of Simple Plan's "Untitled" and rivers of tears.