Because they often give the villain the lines that are socially subversive but true, in order to get them past the censors.
Which is incidentally what makes villains often far more relatable than heroes.
I’m reminded of something Tim Curry said on voicing villains. “The fact is though, that bad guys are often much better written than the good guys, and they’re kind of irresistible because they’re so much fun!”
a reminder from your science witch sister that it’s flu season, and haunting graveyards at midnight or walking barefoot in dark forests becomes much less romantic when you are ill, so go and take your vaccines and do your part to ensure herd immunity for the sick, the elderly and the young.