The Crusades were a response to Islamic military aggression and I am damn glad the Crusades happened as I don't care to live in a muslim theocracy. If you don't like the result you can vote with your feet and move to a country controlled by muslim idiots.
I consider the Protestant Reformation to be a good thing as well since it helped break the RCC grip on power in Western Europe, the Priests who molest children would have never been locked up had the reformation not happened as just one example of a benefit to stripping the RCC of power.
I have a great aunt, Martha Pennoyer Corey, who was hanged at Salem Mass. and I don't approve of that but the last witch trial in N. America or Western Europe was quite some time ago.
BTW the Civil War involved violence. Is that also a bad thing in your view? I ask because IMO letting Islam rule the globe would be a real bad idea as would letting the RCC retain their grip on power they had pre reformation. As it turned out doing away with slavery in this country involved bloodshed. IMO doing away with slavery is a good thing.