Class Homogenization.... Why do you want it?

[ChaozK]

The way i see it the roles for each job are well defined
PLD: Passive Damage Mitigation Tank based on direct damage -
WAR: Reactive Mitigation tank based on HP/ DMG output
WHM: Burst/AoE heal specalist
SCH: Single target heal special/ Support
DRG: Low Skill Medium to High Damage Melee
MNK: High Skill Extremely High Damage Melee
BRD: Low to Medium DMG Ranged/Support Class
BLM: Low Skill/ Medium to High Damage Ranged
SMN: High Skill Extremely High damage Ranged.

Not to nitpick but your addressing of the dps classes is pretty off and narrowed down.
For example compare a standard SMN rotation to a standard DRG rotation. I play a lot of MNK and DRG at endgame and i can guarantee you that skill gap is very minor. Should be more like this:

DRG: Burst/off GCD based melee dps
MNK: Stance based/ sustained melee dps
BRD: ranged dps/support hybrid
BLM: Burst caster dps
SMN: Pet/DoT based caster dps