I think honestly the RMAH ruined it more than the AH. The RMAH limited the amount of GOOD items being sold on the AH... because the good stuff was always traded over to the RMAH, which only cashshopers have access to. I find this quite unballanced and unnessasary...Rather greedy. I'm not one to say it doens't belong here and they should get rid of it or i wont play anymore, I just refuse to ever use it. I grind every coin i make and really enjoy doing it with my friends. I just wish the prices weren't so damned high because of how cheap gold is on the AH. Honestly though, we have a few things to contribute to that.
RMAH 1mil = 1usd, on release. So bots ALLLLLL over the world started botting money, selling it on other websites, this made it even harder to get it. So then some bots were like "Hey, we can make so much, lets take advantage of it in game" and started sellin it even lower and lower till suddenty, 1mil = 25 cents. It's crazy. Now everything in game for NORMAL players who don't swipe credit cards in their buttcrack to play, we have to go out of our way farming hard and for a long time just to make enough to SLIGHTLY upgrade our gears. Because of a little thing called inflation.
I honestly believe that if the RMAH didn't exist, or gold couldn't be sold on the RMAH, we wouldn't be in this predicament we are now.
But at the same time, I can argue, it's made legendaries a lot more affordable if you are farming for them in game, but at the same time, now when you get a ledgendary you're like "Dammit, not again...I'd rather have an extremely OP rare..." that isn't how a ledgendary drop should make you fell....
Wish they could bring back THAT luster, but it's gone. Now we have to deal with whats left, not that it's bad or anything, just needs work.
Over time I believe Diablo will get worse and get better with time. Hell, 7 years to make a baby, 21 to allow it to drink and live a wild life, right? ...Diablo doesn't drink? ...Oh. Hm. Well, you get what I'm saying.