In DF, people often quit if the group doesn't succeed the first time. People go into DF expecting other people to be experienced, have great gear, and succeed the first try ... which is completely unrealistic.

I enjoyed using DF until I reached Garuda/Titan HM, where it became clear that the difficulty was greater than what DF pugs could reliably handle. I eventually beat Titan HM in DF, but it took so many tries that I kept at it more to see if it could be done than because it was fun.

FFXIV should rethink DF. There should be content tuned for DF, and content tuned for coordinated groups. The coordinated content should simply not be on DF.
Easier versions should be on DF for pugs.

This would make FFXIV more clear about the target audience for content (groups vs pugs vs solo), rather than creating content that's too hard for DF, yet suggesting that it's accessible to pugs by putting it on the DF.