I have problems with Diablo 3, but I don't quite agree with what you're saying.
Diablo has never been known for its story, in fact, honestly, Diablo's story is pretty bad if you look at it retrospectively (and yes, I'm including Diablo 1 and 2). Diablo's greatest strength was the atmosphere it created in Diablo 1, which unfortunately, was lost in Diablo 2 and never reclaimed in Diablo 3. If you were a new player to the Diablo series, I could understand your disappointment or failed expectations in the story (since this is what people look for in a game now), but as a veteran of the series, you really should have known better.
Now, let's talk about itemization. I have problems with the way itemization is implemented in Diablo 3, and I have problems with the drop rate of usable items in Diablo 3, but I don't agree with what you're saying at all. First things first, I have found 4 legendaries and 1 set item. Aside from the 1 set item, I actually did not find any of those items via elites or bosses, but rather from jars and "white" enemies. My MF was fairly low too at the time, so that's irrelevant. 2 of my 4 legendaries sold for quite a lot, the other 2 were trash. My one set item was also trash. What I want to establish is the random and gambling factors involved in loot based games like Diablo. Just because I've found 5 of these items in my playthrough doesn't mean you'll find even one. Under normal circumstances, this doesn't really mean anything to be honest, as long as what you are finding is usable.
Therein lies one of the major problems with Diablo's itemization system. The vast majority of stuff you find on your own (with some possible exceptions, most notably in rings/amulets) is completely useless to you where you are at in the game. A lot of people talk about Inferno when they mention this (and I can verify that), but even when you go back to earlier difficulties, the majority of drops I've encountered were totally useless to me for that particular act and only useful for previous acts/difficulties. Although I feel that legendary/set items should be slightly buffed in terms of drop rates (and actually, legendary/set items need to be buffed stat wise too, the weapons in particular are almost useless), it would be fine if they remained as is if you could STILL FIND USABLE ITEMS FOR YOURSELF, which you can not (unless you have god like luck).
As for the Diablo 2 argument...well, I'm not sure what you're remembering, but the vast majority of set items were complete trash in LoD (remember that set items did not exist in D2 original). Finding trash set items is no different than what we're currently seeing (trash rares, or yellow). Uniques (or legendaries as they are now called), were also mostly trash except for a few particular, highly coveted items. Yes, I did find more uniques in Diablo 2 than I did in Diablo 3, but how many were actually usable or tradable? Only a fraction of them.
As for the AH, yes, I agree that gold is currently (still) inflated, despite the fact that it is stabilizing. As for not being able to buy anything? If you're not at level 60, it's a moot argument. The stuff that's tens of millions is the stuff that's way overpriced. That being said, it's not difficult to amass wealth in gold if you're savvy with commodity markets (this is no different than trading in Diablo 2, it's just more efficient now). Buy low, sell high. Do some research into the type of gear that is highly desirable, look for items that are clearly worth more than what they're selling for, buy it up, and then resell at a higher price.