I thought it too, the tanks are in worse position than healers because DRK not played enough (same for MCH for ranged dps).
But, in our case, SCH is played too much and this is a problem too (+ WHM issues, +AST Noct issues, etc).
I think SE can rework DRK without really to take into consideration the others tanks (same for MCH).
They can't tweak only WHM to hope things would be better. Every job need some king of rework to be able to not have a dominant healer (SCH) and a healer a bit far behind (WHM).