For example, since OS4 apparently requires  24k  party DPS, if your  tanks do 6K combined and LBs do 700, it leaves 17,3K  DPS for your DDs  alone. That is 4325 DPS for each DD.
A PLD   doing 3k DPS would currently rank 87%, a WAR 97%, and a DRK 92%.  So your   tanks would have to be in the top 3-13% of all the players  for that  job  in the whole world.
For DDs, 4325 DPS would mean 98% for  BRD,  97% for MCH, 95% for NIN,  94% for RDM, 93% for DRG, 77% for BLM  and 75%  for SMN. So for any of  these jobs, they would have to be in up  to the  top 2% in their job. Of  all the players in the world. (It would  only require 56% for MNK and  31% for SAM  though! 

)
Now tell me  with a straight face that it's completely  fine to expect  that kind of  performance level from your DDs and tanks  (particularly  if you don't  happen to have PLD, MNK or SAM in your raid  team), 
to literally  expect them to be some of the very best players in the whole world,    all 6 of your other party members, while you and your healing partner    would take no responsibility whatsoever for DPS. Please tell me how  it   would be a reasonable expectation for the tanks and DDs and if they    wouldn't somehow happen to succeed to be the world's best and wanted    their healers to contibute, they would be "shifting the blame".  
