In that case, however, Drow are the descendants of elves that followed a god that betrayed Corellon. They aren't innately evil, they are innately good/chaotic and programmed to be evil/lawful (by DND logic).
Orcs are theoretically opposite. Evil/chaotic by essentialist, divinely mandated nature and capable of learning otherwise.
More importantly, they're people the PCs can murder for gold with no discussion about morality... And while that's convenient for some DMs it does have some very, very obvious problems.