A lot of fiction/media tends to reflect current values and trends in society at large; a lot of the work in the older days tended to have occurred during a time when there WAS a face to 'villainy' (even if it wasn't a single person) and so, subconsciously or not, the media would play off these fears.

I think nowadays, with big corporate and government corruption, villainy has moved away from a single face to a big, unknown force that may or may not be hard to face.

As for the evil within oneself, I think that has always been a common theme since the beginning of time. Even religion has addressed it from its onset, no matter what religion.