The game has more interesting quest lines then Vanilla ever had. It has more story development, and it certainly has interesting characters. The problem is you don't seem to find any of those to be true but they certainly do exist as truths of the current game. Perception is a wonderful thing and it seems to be coloring you into the position that Vanilla is greater then everything when in reality Vanilla wasn't all that great.
And if Vanilla WoW existed in the market of today it would be a failure and have even more criticism then the current content.