The damage spreads for the top red mages and the top BLMs are within 9% of each other for halicarnassus and within 4% for neo exdeath. This alone makes the "higher" personal damage contributed by BLM not worth the mobility headache, again to say nothing of buffing the party with embolden.
I don't deny that yoshi p plays the game but we who play the game to min-max and speedkill are not talking out our butts. Devs don't balance things for casual gameplay, they balance things for highest level.
Lastly, if you honestly can't see how raising 5 people in 10 GCDs with almost no ramifications is overpowered, then I have no need to argue with you about it any further. They've said for years SMN having raise was overpowered, which was then balanced by a long cast time, a huge MP dent, and basically requiring swiftcast. Now RDM can crank them out like candy.
