Could be that they had some misunderstandings or misinterpretations of the comic's message or themes. Or perhaps they were influenced by some external factors like extremist groups or bad publicity.
Amy might have been in a bad mood and acted impulsively, without really thinking about the consequences of burning Jo's novel. Maybe there was some underlying conflict between them that led to this extreme action.
Well, when we talk about a 'burn the boats' story, it often implies that someone is making a bold and decisive move by eliminating any possibility of going back or changing their mind. It's like they're giving themselves no choice but to succeed in the chosen path.
Maybe they have a very extreme view. They might think light novels are full of unrealistic content that misleads readers, especially young ones. So they want to get rid of them all by burning.