No, when they nerfed mages (permanently) in XI it didn't destroy them or finished the game, people just couldn't be lazy and destroy things like they were doing. The only thing that 'destroyed mages' was the enfeeblement adjustment they made which they made resistance too high and fixed.
SCH came 'destroyed' out of the box, it was a RDM that couldn't enfeeble as well as RDM nor heal as well as RDM/WHM nor nuke as well as a RDM/BLM, therefore they adjusted it which caused people to complain that it was too good and it pushed BLM/WHMs aside. So at no point in time did they ever destroy mages in XI, the only time the roles shifted was in ToAu when mobs didn't take magic too kindly, after 4 years of every mob in the game bowing down to BLMs (Manaburns)..that was a well deserved change.
The difference between XI and XIV is that if they do any changes in XIV it will be severe because the stat calculations are already pretty severe and unbalanced to begin with, so if they nerf BLM, no, XIV is not finished, it just means people will actually not be able to stack BLMs and beat everything...if anything it'll help the game more than hurt.
I understand BLM is probably your only class/job but you have to realize, when the world no longer revolves around you, people make up for it.
Thing is, I write that knowing the fact they still have some changes left to do regarding skills, while the skill selection is done, they stated calculations are still an ongoing process.
