So, let's dive in. That's how it works, case closed. Violence has results in the world, at times unpredictable. Committing violence has results for the committer. People assess risks - including that of other people, and a violent person is a risky person.
Violence takes up time, energy, and is risky.
The problem, simply is, heroes who use violence are often poorly written, ignoring the results, causes, and implications of violence. The act of violence affects the actor, as does encountering violence. I strongly recommend, if you are going to write extended violence, read up on Post-Traumatic Stress Disorder and veterans of wars. People aren't going to ignore a violent whirlwind of destruction even if it calls itself a hero. You can only spend so much time and energy kicking rear end.