The problem is that Square has a proven track record of leaving bugged encounters unfixed for long periods of time. Remember when Steam Cleaner stopped popping for a few months? Remember when Jailer of Love was nigh unkillable?
When you're challenged, that's fine. That's great. But when you're unsure whether the brick wall you're running into is a challenge or a glitch in the game, it sucks all the fun out of trying. When ToAU is released and we get some new mega boss mob to fight that wipes the floor with everyone, will your first reaction be "This will be a test of our skills!" or "This is probably just bugged, screw it"?
The seeds of doubt have already been sown.
</rant>