Looks like you're working from an interesting collection of "alternative facts" there. Available character power was escalated beyond what content's highest difficulty setting could cope with.
It was asked that there be an environment where the amount of character power they made achievable had a purpose. • They delivered a setting that blanket reduced some character's power, while providing additional power increases to other characters (both immediately by proxy and eventually by rewards) in said environment - and some of the power increases worked outside of said environment. • They didn't give what was wanted.
It was asked that such an environment be there for those who wanted an increased level of challenge. • They delivered an environment heavily incentivized/rewarded enough that players with no interest in seeking additional challenge were driven into it. • They didn't give what was wanted.
It was asked there be an environment that incentivized/rewarded a group of characters to play as a team vs a group of characters soloing the same instance together. • They delivered grouping rules/mechanics that were incongruous with existing ones (Bravery Bonus vs Reaper, Epic level lockouts) and hindered group formation. • They didn't give what was wanted.
To the best of my recollection, literally nobody asked for a new harder-than-Elite environment that would provide a more time efficient leveling arena (I welcome links/quotes to the contrary) - but that's what they delivered. • They did not give what was wanted.
Saying Reaper is the Devs giving players what they wanted is at best revisionist history.