It's not about something being in XI, it's about XIV needing something they should have added first.
It's totally about that, just about everything (non balance related) that people complain about regarding jobs is borne out of some notion they got from previous FF titles.

Examples:
- RDM melee crowd in XI
- SMN's complaining about their Egi's in XIV
- People who want XIV DRG's to have wyvern pets

People seem to think "Oh I LOVED Job X in FFII, it should be exactly the same as that in every FF game for eternity.".