I think it's social conditioning and lack of mental health resources. Girls are strongly socially conditioned to "play nice" and get along at all costs, which tends to lead to more rules following. Boys are often socialized to suppress their emotions while at the same time are allowed to act out and encouraged to be tough and macho. The bad boy act is romanticized and violence is at best tolerated and at worst idolized.
So you have men who never learned how to deal with their feelings who also are used to having a physical, often violent outlet because that's the only acceptable thing they know.
We really have failed our men and our boys. I consider myself a feminist and I can argue about the shitty things that men do to women with the rest of them, but what almost always gets left out of the argument is that men were raised to be this way since they were boys. Society, do better. Stop raising girls to be accountable while giving boys a pass. Let your boys (and girls!) be rough and tough but teach them tenderness, compassion, and that emotions are healthy.
Teach your boys to become men like Aragorn.