There's only so much you can do with 3D Rendering. Doom 3 is the closest I've seen to real imagery using a 3D engine, and at times even those models look cartoonish and fake.
I feel that the character designs have a unique feel to them, and are unique to the MK universe. They may not look real, but it sure beats a monster mask and lee press on nails spray painted silver as teeth. ;)

Zynthetic is right. There really is only so much you can do with 3d. With the detail in doom 3 I'm guessing it took them a loooooooooong time to get the models to the detail they needed. It's not easy and with all the stuff MKD has in the game it would be hard to put models with the detail you are asking because ps2 is limited and so are the dvd's. Besides I don't think fans want to wait another year just for better characters models lol. Maybe in MK7 this could change. It just takes time, effort, and money (which I think midway is limited too with it's losses).
That's my 2-cents.
Enjoy. :-p

i don;t have a problem at all. they are the most detailed charactors the series has seen yet, along with the best graphics, and smoothest animation. so i have to say that i don't really agree.