What you don't get is that hopefully, most powergamers don't give a **** if others can obtain the same gear through ASAH, they're actually the one selling it. About no one cares about the prestige (sure some do) either in a PvE game, you got it all wrong. It's about having a reason to run the only thing that you like : the challenging stuff.
If you give me no reason to run the challenging content of the game, well i'm just on a break unless i'm still up for a thousand TRs. There's just no way around it and after 6+ years of playing, let say I personally don't feel like chain TRing all the time anymore.
And exactly as you said, having the best gear isn't exclusive to the power gamer. Make it sellable, problem solved as for what concerns you.
Finally, being a power gamer has nothing to do with gear in a game where gear doesn't matter that much, I agree. Though the playstyle of a powergamer usually leads him to obtain the best gear since he's looking to min/max as much as possible with the time he has on hand. So yeah, you just sound like another casual who thinks he has mindreading skills but sorry, you don't seem to do as your assomptions are false.
The old system was even worse when it comes to being casual-friendly.