Dirigible
Explorer
There is little true interaction between characters; since the games are meant to be played by a single players, you have only scripted NPC interaction, and most of that is terribly superficial and rather dull.
Play Planescape : Torment.
CRPGs do not do a good job with emotional content. Oh you might get frustration, even anger, along with some Three Stooges-level humour, but rarely (if ever) do you get wonder, horror, joy, misery, sadness, simple pleasure and the full range of human emotion.
Play Planescape : Torment. The only computer game that has ever come close to making me cry. And it got most of the other emotions in some measure.
Most plots I have run across have felt grossly contrived
More contrvied than, say, 'you all meet in the tavern'?


This brings up probably my largest gripe against crpgs -- they are all about killing. Oh there will be the occassional episode in the game where you are not supposed to kill something, but this is an extreme rarity, usually meant to trip you up
As Zappo says - you can kill the final boss AT LEAST THREE WAYS by talking to him. Admittedly, there are only a few other times in the game you can get away without killing things (but far more than, say any BG games).
Still; you're right that a CRPGS cannot compare witha good (or even average) face to facer.