I have never noticed this trend at all but maybe its just cuz there are so many damn NIN in this game so its much more likely to encounter one who is an ass. Why would you not play NIN? Most consistently the highest single-target DPS in the game and, unlike MNK, much harder to suck at. There is the "cool" factor, the "new job" factor, and the "OP factor." A lot of people started DRG cuz they thought DRG were "cool" but many dropped it once they realized how underpowered DRG were.

Then again, BRD is still an extremely played job (not surprising as I still considered them the most OP job in the game when all things are considered) but apparently you don't have any issues with them. Most likely, its just your own personal experience.