Maybe she has a history of lying or her actions don't match her words.
It could be that her motives seem shady or there are contradictions in her story. Maybe other characters have reasons not to trust her that are shown earlier in the manga.
Perhaps she's been shown to have ulterior motives before or has been involved in deceptive situations previously. Maybe the plot gives hints that make us question her credibility.
Because one side might be biased or incomplete. It could be presenting only part of the truth to serve a particular agenda.
Maybe because they think the heroes' powers and stories are too far-fetched or unrealistic.
Well, for one, teasing manga might hurt the feelings of those who are passionate about it. Also, it can create a negative atmosphere among the manga community. We should encourage and support rather than tease.
It could be that the story contains uncomfortable or disturbing content. Or perhaps we simply don't have the time or energy for it right now.
It could be that her stories have some kind of negative or disturbing content that we'd rather avoid. Or perhaps they just don't match our preferences or interests at the moment.
Because reading the success stories gives us a more comprehensive and detailed understanding. Believing alone might lead to misunderstandings or incomplete knowledge.
Maybe it has lots of plot holes or doesn't make sense. That could be a reason not to believe it.
Maybe she has a history of deception or has shown unreliable behavior.
Maybe it's too scary or inappropriate for some people. That could be a reason.
You shouldn't hold up manga because it disrupts the normal distribution process. Publishers have schedules to keep, and holding them up messes with that. Also, it could potentially lead to legal issues.