I think there is a general lack of sophisticated and noble evil/dark/bad races in games. I tend to play good/light sides, but I also tend to jump at the (very rare) chance to play the bad guys if they're not wart-faced, snot-nosed, sniveling snide snakes living in decrepit hovels.
I don't know about that. I would have to argue. In fact, I had an argument with somebody else a while ago about how the evil guys were always cooler than the good guys.
I think its a mark of the times. Now its the late 00's, but back in the 90s evil dudes were playable all the time and they wern't all wart-covered or snide snakes. Things like the soviets on C&C, drow and half the characters in baulder's gate, shadow the hedgehog (we was pretty evil until the Sonic teamed managed to mess his archetype up in every game since adventure 2), non-strogi vampire counts in warhammer. Heroes of Might and Magic's infernal characters were generally pretty sophisticated, and so are most mad-scientist archetypes. I wouldn't consider kerrigan from starcraft to lack sophistication or nobility. She is wart-faced, or something similar to it anyway, but she's really intelligent and still shows humility at times. Sephiroth is very pretty and playable in FF: Crisis Core. The plant chick is evil (I strongly suspect) in Demigod, and she doesn't appear to lack nobility.
Using warcraft as an example, since they have so many villians, Illidan is a noble villian. He has horns in Warcraft 3, but he didn't always have them. He holds love in his heart, and doesn't actually want to fight his fellow elves. (if they broke continuity in WoW: BC, I don't care and don't bother telling me. It was a good story until the WoW writers got their hands on it). He just wanted power. Originally he thought his power would please his love when he first started to turn into the demon during the war-o-the-ancients, but of course she didn't like it and she was already sleeping with another dude with horns (his brother to boot). When they had to destroy the Magic well, the thought he was doing good by saving some of it to start another well of magic in their new home. It is like the Lex Luther effect, he does things very bad but things that in the end his old friends will realize it is a good thing and forgive him.
I bring him up because I suspect most strategy game fans have played Warcraft 3. it is about as mainstream as it gets. And there you have it, a noble sophisticated and playable villian. That also being said, most* of the examples I give are actually rather old, and that is probebly because of the economy and such. Movies have similar trends. Right now good guys are bright and shiny, bad guys are evil and twisted. Go back about 8 years and everybody had a black-boarder to some extent.