Look at the numerous thread either here or on reddit where people ask "What is the best <insert_role_here> to play ?" or "How do I spec my Zeta ?", etc...
The answers are always the same "For endgame raiding, chose THIS (And then people start to insult each other because THIS is "bulls*t" or whatever) but for other content, play what you like because everything is fine"
And then realize that "endgame raiding" is the goal of, again, only 5 to 10% percent of the community.
People on this thread reacts like one spec will give uber-ultra-DPS-Turbo-Edition and the other will be only useful on killing critters...
For the BLM, what if only "Ice Mage" get the higher tiers of Umbral Ice, or a proc where after casting Blizzard, the next Blizzard III or Freeze spell has a chance to put a "Frozen" debuff for a set duration, and that a Frozen enemy receive additionnal damage when physically hit ?
Which one is better ? Well, one is a better pure self DPS, but the other can be better as a whole depending on the party DPS. You could easily create traits and alter spells to make specs different, and you'll create the same flame wars as now between different jobs...
And those purposely forgot that the meta changes several times through the lifespan of an online game. Isn't League Of Legends famous for switching back and forth what is the "best champion" because people still found new ways of playing them ?
They want to play it safe because players complain as soon as they have to "think".
Diablo 2 ? Let's imagine some buils and try lots of skills. Diablo 3 ? Let's have all the skills available because we don't want the "burden" of creating our own character.
FFXIV v1 ? Plz, remove the physical level, it's sooooo complicated to spend our stat points wisely if we wan't to create either a specialist or a jack-of-all-trades.
And yes, I realize the the physical level had flaws in v1, but instead of adjusting it, they decided to scrap it completely because people cried over and over. So, in v2, they gave stat point distribution back, yeah ! But it's useless, since almost every job use only one stat.
And they even remove the effect of STR and DEX on something else than attack power. Technically, they could fuse the two under "physical attack" and it would be the same, since gear are restricted, already.