Healers are punished too hard for dying

[Absurdity]

The main reason why DF isn't used for challenging content is a cultural one. NA and EU just use PF, form their parties there and go with control over what they want to do, add a PF description on prog points, specific strats, etc.

JP just uses the DF in a more anonymous group approach, where everybody is expected to follow one specific strat, get in, clear, get out. If you played on JP for instance you'd probably not use PF much for endgame content.

Last time I checked even JP only uses DF for actually clearing a fight and it is expected that everyone knows what to do when queing up through DF. They still use party finder for learning.