In the course of a game that endeavours to recreate a period or geographical location with a modicum of fidelity to historical reality, players are doomed to stumble into events, attitudes, and conventions that will duly vex the workings of their modern minds if they're unprepared. The relative ubiquitousness of violence in medieval England is one of them.
I think that because we play in a setting that mimcs a real time and place to the best of my ability, and certainly more realistically than hack-and-slash Hollywood portrayals, it's easy to conflate the game world with the world we know simply because it's more like reality than films or video games are.
This first came up when the party chanced into a shepherd beating hell out of his servant boy in a clearing in the woods. When I ran that encounter, I had no intention whatever of it being any sort of dilemma for the players to 'solve'. And yet, looking at the situation as they did with modern eyes, they saw child abuse and wanted to put a stop to it. They ended up in a quandary, and decided perhaps that interference might do more harm than good, and they eventually walked away, feeling none too sanguine about the whole affair.
The thing is, the very characters the players are running would, in all probability, have been beaten just as severely, and rather frequently, throughout their own childhoods. The players may see unlawful cruelty, but the characters would probably just see the everday discipline inherent in childrearing. In fact, at this time and in this place, parents who neglected to beat their children frequently were seen as irresponsible parents.
This is a mindset that continued until, really, just the last couple of generations. The idea that 'it's never okay to hit a child' is actually a quite recent invention. You'll see a different set of standars and values when reading older books meant for children. I recently came across a .pdf of the novel Little House in the Big Woods by Laura Ingalls Wilder. It's a lovely look into the lives of the American pioneers, and shows an admirable culture of responsibility and self-determination. It also, for better or worse, features several scenes of parents brutally beating their children. In one scene, little Laura slaps her sister's face in anger, and her father promptly calls her over to be whipped with a lash he kept hanging on the wall for just that purpose.
'But Mary said--'
'That makes no difference. It is what I say that you must mind.'
These sorts of scenes were played down in the Little House on the Prairie television series, filmed as it was in the 1980s, when corporal punishment at home and in schools was already on the wane. In the books and the televised versions alike, Charles Ingalls was presented as the paragon of fatherhood and manly virtue (putting aside for the moment that the real Charles Ingalls did many things that were questionable at best, like defaulting on rent and then sneaking his family out of town before the landlord could catch them). The point was that morality was absolute, and would admit of no excuses.
Within the context of such a cultural framework, it should be expected that adults are also going resort to hitting each other, sometimes with objects that quite a bit more damage than hands and switches, as a means of solving problems.
In our last session, the entourage came upon a certain tale, recorded in Ralph of Coggeshall's Chronicon Anglicanum, one of the few history books available in our campaign world, in which a 'merman' or some sort of mysterious acquatic humanoid had been captured in a fishing net a couple fo centuries before our game takes place. In Abbot Ralph's record, the merman's captors wanted to find out who or what he was, but he wouldn't talk, so the first thing they did was to torture him. I related this and other details to the players merely in passing, but one of them cried out in apparent objection, 'But why did they torture him?'
'Because he wouldn't talk' was the answer. Simple.
This is the way things were.
If the reaction on this realisation is still something like But that doesn't make it right! then spare a thought for the upbringings your game world counterparts would almsot certainly have endured. If the PCs hadn't been smacked around and learnt that violence is the way to deal with problems, how likely would they have been to embark on a career that involves killing people?