For me, aggression and violence are a sign of weakness and lack of ability to solve problems in a civilised way.

Absolutely! It's succumbing to base aggression. Here in Australia there's domestic violence case after domestic violence case. Men asserting their dominance and throwing acid or beating women to death. Weak, fucked up men who can't control their emotions, because they were never taught to. Fix that and we fix a LOT of problems in the world.