Black Mage doesn't need a nerf. Here's why.

1. MP already limits your Damage output. Black mage is best suited to a quick 2 min or less battle. After that, they need to rest or conserve MP to keep up their DPS.
2. Mobs HATE getting hit for large damage at once, means BLM's really have to watch their +EMN. Because most 'event' mobs will EAT a BLM in 1-2 hits if they pull hate. Melee DD's can at least take a hit or two while tank gets hate back.
3. BLM is one of the few Jobs in game at moment that better gear does actually trump player skill. Therefore, being a decently geared BLM is an investment. Don't get me wrong, you can't just have mack-daddy gears and expect to be an awesome BLM if you don't know how/when to use what spells and abilities...but just knowing how to use your spells and abilities and using 'meh' gear, won't help you much on high resistance mobs like Garuda. One resist=messed up combo, downtime for BLM...so in this respect, it is always going to be a class requiring above average gear. (=expensive)
4. Did it ever occur to all those in the 'nerf blm camp' that the reason BLM setup works for so many battles right now is that we're fighting Mobs with High Def, lots of AOE and lower Mag Def? The fact that BLM reigns supreme should be a no brainer.
5. BLM is supposed to be RAW damage, that's it. The 'enfeebles' it has are all (with the exception of Flare) Mob mobility stopping, slowing, sleeping or -emn reducing for a reason. They are BLM's only defense, and they are intended to help BLM's keep the mob at a distance....so they can keep nuking.
6. Yes, currently the community over uses BLM. I think most of us can agree on that. But the reasons for the overuse aren't because BLM is too powerful (which IS why WAR is still tank over PLD) but because there are some basic flaws in dungeon/primal battles right now that favor BLM's style. If SE would reconsider speed runs=5 chests, AOE boss attacks, requiring more movement in a fight, and create some magic resistant and/or magic immune mobs, we'd be whining about Lancer or Archer or Warrior stacking... (which by the way HAS been whined about in the past).
7. A majority of the 'endgame elite' shells happen to have a lot of people in them that Main Black Mage, Bard or Monk. This is why you see those combinations so often. They are simply playing their favored classes to clear new content, but then their method becomes 'the way it must be done'.

Now about Archer/Bard
Yes, when people stacked Archers to do darkhold Buffalo etc, I'm sure archers had a blast. But square decided to morph Archer into a DD/support class hybrid. When they did that, they HAD to reduce Arc/Bard damage to balance things out. Also, while I know most parcer's don't calculate this, think about how much damage a Bard is indirectly responsible for by giving the party boosts? My White Mage rarely gets to throw out any DD spells with the exception of the occasional Stone (which I cast to make the BLM's more effective btw). But without me, the party's damage would suck 'cause they'd be dead. A 3 second recast when you WS is nothing...it doesn't even change your gameplay.