its more a case of is it's view on alignment valid?
I say yes, what Vile Darkness + Exalted Deeds says is evil is, in fact evil, but there are those who insist either that its not used in Living Greyhawk, so not valid, or that its not 3.5, so not valid.
Personally I go with Wizards wrote it and an increasing frequency of supplements include Vile feats for villains: Its Authoritive!