Wouldn't let me put all text all in one post. I'll post it in general.
1) The current fate system will work for the time being. But fate grinding gets very old. It's too easy and boring.
2) People generally go where the best exp is at. Fate being the current.
3) If current dungeons and guildhest provide the best exp. The world will be a ghost town from people constantly doing them.

Classic ffxi party sometimes got boring too, but mix it with difficult fate battles and not boring wildlife, then it will be more fun.