Actually I suspect the origins of the term do in fact refer to scientists. Victor Frankenstein was in fact a scientist in the traditional sense (nor was he ori

Actually I suspect the origins of the term do in fact refer to scientists. Victor Frankenstein was in fact a scientist in the traditional sense (nor was he originally written as a villain). But yeah, it's a lot easier to make a "mad engineer" villain than a "mad scientist" villain. Mad scientists tend to be more suited to being secondary characters-- somebody so obsessed with discovery that their goal of scientific discovery conflicts with the protagonist.