I personally like it, I feel it adds a bit more depth to things, otherwise i might as well be fighting cardboard cutouts with angery gerblin faces drawn on. But also, if I'm playing a character that would kill the goblins, then I'm going to try to kill goblins.
Plus it makes it possible to include the monster races in a party without it being too insane, which opens a huge door for some of the most popular fantasy races to become PCs.
