Different engine indeed and also different priorities. Man, if you want uber graphics in a CRPG then you got your priorities in very much the wrong place. The game could have ASCII graphics as far as I care. In a CRPG only two things that really matters is the story and character development. graphics, sound effects, and music is just candy.
Games that have substance don't need uber graphics to be good. Shooters like Farcry have zero substance to them therefore they need the uber graphics in order for them to be marketable.