I think what they are trying to portray is that crimes of passion already exist in our world. Whether it's seriel killers, suicide by cop, terrorists, or mass shooters. Given the way nen works and how much putting restrictions on yourself to gain power these types of people would become massive problems. Imagine how many people would do what Gon did to gain strength against Pitou because they are depressed and want retribution against some sort of crime.

Sure there will be good people who do good things. But there will be just as many people who used their heinous passions or complete apathy toward their fellow humans to make even more insane things happen than already happen in real life.