You know, having more time to ponder the ending, Larian really dropped the ball IMO. Just take it from movies and other media, you can do a sad or disappointing ending, but you have to do it right. I think I felt so crappy about the ending because they did not put enough effort into it.
What they should of done was immerse the player in the actual dissapointment. You could do this by giving a longer ending cut-scene, as well as some better transitions. Maybe a first person view of getting stuck in the crystal, some kind of struggle of imprisonment, something.
Still a great game, just a completely lackluster finish :|