"balancing" some jobs

[Lymberey]

4) Black mage is now added to the mix, 3 seconds freeze with a REALLY high damage output, shields and AoE freezes with a HIGH damage and gap closers with a HUGE burst. BLM needed a small buff on the dot potency, no idea who thought it was important to literally make BLM a unkillable CC monster.

To be fair, AoE potency and CC of Black Mage remains the same, 8k and 3s for 3 stack. So I believe what you were referring to was 12k on primary target, which is very high during LB.
However 10K is fair enough, 12k is a bit overbuff imo. It does help BLM a lot when dealing with solo target and people who spread out. They can make it hit less with 2 or more targets, but that would basically control the movement of the opposing team for the rest of game.
Does it make sense for BLM LB to be strong? i believe it does, as BLM LB is the most lengthy LB without immediate results while making the BLM an even more obvious target.

16k/16k on 'Burst' is a fair trade-off as it is a 0/5y spell with cast time and need to sacrifice positioning and a mobility option to use offensively, unless the target is diving or overextending.
BLM is far from 'an unkillable CC monster' because you still need 2 DPSs to kill a full MP Black Mage efficiently as before, or a skilled NIN. Still, it does make BLM harder to solo kill.
BLM is always a CC monster, but people chose to ignore them because BLM used to barely deal immediate threatening dmg, now they are almost guaranteed to get a mark on their heads. Not to mention the 'auto mark' coming from their LB.

There is no need for hardcore nerf to BLM, just a bit nerf or nerf with some buff to some aspect.

[Thorime]

However 10K is fair enough, 12k is a bit overbuff imo.

They overbuffed BLM, that's my point. It didn't need that many buffs since it was already in a decent spot, maybe just a bit of a DoT buff or something but not that overall huge increase.