Except it's not blizzards economy, it's ours, it's as free a market as you're likely to see. And quite frankly, what's happening is a bunch of mid tier players who thought they were "serious" about the game because they used flasks and potions are getting priced out of the market by the tier that is actually serious, and that's fine. There are cheaper options, and the content can, in fact, be done without them for the time being. All the gold transfers are going from player to player, so it's not like blizzard is somehow benefiting. The "vast majority" right now as you put it should be sellers, not buyers.
Now I agree the professions are terrible and the gearing is wonky. But those problems have nothing to do with the economy.