So you can't think of a single opinion that would make someone a bad person? Not one? Then you must not believe a 'bad person' exists or that any action makes someone a 'bad person', unless you'd argue that actions don't belie opinions.

Try this: "Jon believes puppies should be bred only for fighting, and pits them together from a young age to cull the weak. He starves them to make them ornery and more likely to fight."

Is Jon a bad person? Or does Jon simply need to be educated that we've all come together and decided dog fighting is immoral. This is not a 'creature of his time' scenario, he knows people look down on dog fighting and still knowingly and intentionally inflicts pain on them for personal profit.