I think it's the other way around. They have always wanted to do those cruel things that have real victims. It took them many years of dedicated, coordinated efforts as they slowly inched many systems to align with their insane ideas. The villain branding is just that - branding. Many of them actually like the 'bad guys' in those stories, especially if those bad guys are portrayed as strong, uncompromising, militaristic, inhumane, and having simple, memorable iconography that instills fear - the more allusions to real life fascists, the better. But that enjoyment follows from their ideology and what they want to do in the world, not the other way around.