Been a BLM since I started this game 2 years ago, I fell in love with the job, is the best job I can play. It really makes me sad to see what ppl call "good BLMs" just because they can do 1.8k+ Thundaga III, that's not being a good BLM, getting high numbers does not equal being good, being good means do good damage, save MP and get no aggro, and most importantly adapt to the PT setup and/or mobs you're fighting. And if you really wanna be that good, find out how the damage is calculated, find out how your job works from the inside, I know I did, look at my sig, and let me tell you, I didn't get a bit of hate from that MB, and mob wasn't dead, Buffalo just got too much HP.
As BLM you gotta worry for a bunch of things, MP, Elemental Skill, INT and why not tewaking some dmg with bonuses from equipment.
If the nerf BLM someday, then so be it, I won't complain at all, no matter how bad the nerf is, I'll just laugh at all the bad BLMs who will.