One reason could be that they face a major betrayal or personal loss that makes them question their values. Another possibility is that they are manipulated by a hidden enemy and end up on the wrong side.
It's often because of factors like time passing or poor storage conditions shown in the comic.
No, Optimus Prime didn't go bad in the original comics. He was always a heroic and noble character.
Maybe it was due to poor sales or not being able to compete with other comic companies. Could also be that their content didn't resonate with the audience.
I don't think so. Usually, in manga, characters have complex traits and actions, so it's hard to say there are absolutely no 'bad' heroes.
I doubt it. A world with only purely good heroes would be quite unrealistic. Usually, heroes face challenges and make mistakes that could give the impression of being 'bad' to some extent.
Hard to say for sure. It depends on how you define a 'bad hero'. Maybe the characters have complex motives that make it hard to classify them simply.
Maybe it has a weak plot or poor character development. That could make it seem bad.
Some comic heroes might be considered bad because their methods are too extreme or they cause unintended harm. Also, their personal flaws and mistakes could lead to this perception. But it often depends on the reader's perspective and the context of the story.
Not necessarily. It depends on the specific comics. Some used comics might feature heroes, while others might not.