I can't really put my finger on what's missing, but I know something tangible is at play here. It can't be nostalgia. I really do think it has to do with the speed with which stories used to unfold, and how they moved from basic to epic over a series of twists.
The best I can come up with is the fact that the more 3D and realistic RPGs become, the less room there is for imagination.
My favorite RPGs are still the party-based, turn-based, sometimes icon-based RPGs of the 80s and 90s. Games like http://www.youtube.com/watch?v=lnIqN37IUmM&feature=related, http://www.youtube.com/watch?v=1KybwxpRQNE&feature=related and the SSI gold box series, http://www.youtube.com/watch?v=bQgd8MO3pOA&feature=relmfu, and eventually Daggerfall which while 3D still leaves plenty of room for the imagination to "fill in the blanks". None of those games have what we'd call "graphics", and Wizard's Crown is icons on overhead maps, but they all have something modern RPGs lack, and the best I can come up for that "something" is that they leave lots of room for the imagination.