The only way I can think of answering your question is by means of being ungrateful or underappreciated. Mabye we see in movies, games, novels, how people are destroying others or the world around them, intentionally, and somewhat unintentionally, until some "monster" or thing comes along, and makes them regret what they did, but by that time its too late. That's not to justify what the monster does, but in that world it simply exists and does what it does, and there isnt much you can do about it. I wouldn't really say you need it, but I will say, ironically sometimes people will end up better off even so morally speaking at times, encountering and defeating a "monster" than if never meeting a monster in the first place. And thats not to say the person couldn't have changed without a monster, they just chose not to. That monster may have, for example, shown them not to simply accept things just because you are given them, and therefore not to take advantage of a situation or others. Although the monster is still a monster, so it may be doing so for it's own reasons and not necessarily to help you out.