This is basically a normal online gaming issue caused by a player made "meta" that is seen in just about every online game out there that either has multiple characters or classes to play as.
I think the problem here isn't the damage output of jobs like SAM that don't have party based utility to offer. Its that the benefit from this job hinges entirely on that 1 person knowing how to do the battle and play their job. While another job with utility will output less personally but allow other party members to perform better. I personally care nothing for meta on any game as if frequently causes large portions of the player base to think that meta is the only way to play the game when it isn't. I do think part of the issue is the hard enrage timers on 8 man content currently making the battle a DPS check. Without it we probably wouldn't be hearing about this as much
