Of course I would be hung up on not getting experience points or rewards. Imagine playing through any FF game again where you are already max level and have the best gear in the game. That sounds terrible, but you are trying to tell me a majority of players like this and feel accomplishment from this? You sound like one of those people that believes everyone deserves a trophy.
So yea I believe this game needs more post game content over all. More options for gearing, and just more content in general for all players casual and hard core, and definately things that are repeatable as a large amount of the content the devs add becomes obsolete fairly quickly. It's possible we may be getting more of that we are getting some weird omega story, hildabrand story, 2 ultimate fights, criterion dungeons.
Now your whole thing about thing about hardcore minority, some people enjoy to play games that challenge them, and there is nothing wrong with that. Most games when there is a New Game + that is typically a challenge mode for people that want more from the game after completing it. In some cases it is just an easy mode to face roll through the game again as it is in FFXIV and there is nothing wrong with that either. But the expectation that everyone is to like New Game + being a face roll with no rewards, and if you don't then you are a hard core player that just wants rewards is just ignorant.
If anything I think it is a mistake on the devs end to not allow you to gain xp from NG+ as it would keep more expansions alive with that incentive as new players come into the game. Instead the answer to that was putting Trust systems through out each expansion. This is one of the major things that helped WoWs downfall was not keeping the new player experience intact and it can be a tricky thing to do as more expansions release. If you can't welcome your new players properly they will not stay.