In recent decades there has been some pushback against the rather Nietzschean sentiment that enduring trauma "builds character", and science can really only tell us so much regarding such matters. And certainly, there are plenty of instances wherein trauma has essentially "broken" people, by which I mean that trauma has made them weaker, less capable, and--to borrow a rather annoying and vague term which nevertheless conveys something akin to what I am getting at--less "self-actualized".
That said, speaking from personal experience, I have found that people who have experienced very little violence--being on the receiving end, that is--or extreme hardship or deprivation in their lives, tend not to respond very well when they do have to face such things personally, or deal with such with regards to others. I'm referring both to physical as well as emotional or psychological violence and hardship. When such comes knocking, such persons are prone to retreating, shutting down, or reacting in such ways that only make matters much, much worse.
Again, this is just my own personal take, and while I wouldn't exactly say that I'm thankful for having experienced a fair bit of violence in my own life, it has helped me both with dealing with irrational violence directed towards me as well as affording me the ability to redirect violence aimed toward others toward myself, in order to spare the other(s). For instance, I've worked with a lot of dogs with serious... issues, stemming from either abuse or neurological complications, and I've managed to spare both people and dogs some potentially very serious injuries--likely to have been made much worse by their having reacted in the wrong fashion--on quite a number of occasions.
It's a rather difficult matter to broach, because I don't wish trauma upon others but I'm also rather concerned about so many being so unprepared, imho, for such.