Destroyed was probably a too harsh word. But the initial success of Diablo 3 centred around the success of Diablo 2. Cant comment on the daily player part since I have no numbers about this for D2 to compare.
Fact is, by the time you got to lvl 60 and tried to go into inferno, the game became very frustrating with no good drops to progress your char. So you had to farm gold coz the AH was now the best source for getting upgrades. So the core problem was the loot system.
Imho, the loot system was linked to the AH, even if the developers said it wasn’t, that was just a big lie (still imho).
You can say that the loot system had to suck, otherwise the AH wouldn't have worked. Now you can blame the AH
The RMAH was not even remotely part of the problem. Heck the RMAH didn’t even exist when the "problem" was already there.
With Loot 2.0, I wouldn’t mind having an AH and RMAH, I prolly wouldn’t even use it. I guess they saw that an AH would not make much sense with such a loot system, so they shut it down.
It's even a good marketing point and saves some resources maintaining it.
To your Point, Diablo 3 was far away from being a great game. Even a indie studio made a better game called "path of exile". Patch 2.0 changed that to a certain point and I thank blizzard for that. But they still have much to do to make this game as great as D2 LoD was I do play d3 again and I have fun with it.
Cheers