Definition of VILLAIN
1
: villein
2
: an uncouth person : boor
3
: a deliberate scoundrel or criminal
4
: a character in a story or play who opposes the hero
5
: one blamed for a particular evil or difficulty
Because the word villain implies that it is bad for the sake of bad. At least to me it does. You could make an argument that 4 does not mean it is evil but it still means that they do not serve the right and proper sid eof things.
A villain in any good fiction has reasons for doing stuff either more complex or more morally justifiable than"lol I'm evil". See: Ozymandias, the Joker, the Templars in the assassin's creed series, etc.
Heck, even your character is, by definition, a villain. He's a ruthless tyrant who upholds one of the worst, most oppressive systems of government ever devised and doesn't even think of alternatives. So really, everything in BM is grey vs black at best.