[DF] Why not have some pure "bad guy" races in DF?

[b-dog]

I have been thinking about the old school D&D and how they had bad guy races such ogres, trolls, gnolls, trolls, orcs, goblins, hobgoblins etc. These races were nasty and evil on the whole; although there were exceptions who were not eviland possibly even good. I just think these races could have been created by evil gods or maybe were corrupted faerie races or whatever, who knows. I mean in folk-lore a bugbear is an evil faerie and goblins are mischievious and malicious faeries. Trolls and ogres liked to eat people. And orcs who were created by Tolkien were considered an evil race or at least very hateful and nasty.

I mean if you want more complicated races then maybe lizardmen, coleopterans, cat-folk and the like would be races that battle over resourses and territory with humanity and they would have a logical social structure. So there would be enough of those kinds of races already so why not have some that are just a bad guy race?