I like the idea of NM (so long as the balance leans a little more casual than FFXI's offerings), but it is hard to justify them when The Hunt is already a very similar mechanic.
I would argue that the reason NM resonate with us so strongly is the idea of unique looking, rare gear. FFXIV has very few pieces of gear that aren't instantly recognizable (when was the last time someone asked you "woah, where did you get that?!") where as FFXI had them in abundance because every zone had multiple NM and almost every one dropped something cool.
But I don't think it's practical to have both the hunts and NM in the game, I would say that instead The Hunts should be expanded to include unique gear drops as well as their standard rewards.