this page has been a bother for a bit so let's vote on whether to keep or not as some of this is valid - especially that the mass-murder of infants etc is not accepted as part of Arthurian lore by the whole.. remember that Doctor from Doctor Who has wiped out entire species and remains as a "hero" too.
also Beowulf, Hercules and other ancient heroes committed mass genocide, infanticide and worse yet are also seen as heroes - this is not as easy as judging by 21st century standards.. much as Hercules was seen as the "divine protector of mankind" by Ancient Greeks King Arthur is seen as the protector of England in his time, whether we agree with his methods or not.
one man's hero is indeed another man's devil but ultimately Arthur is remembered as a whole as a hero.. that's the kicker here.. he is remembered in history as a hero much like Robin Hood.
ask any historian on the real Robin Hood and you'll find tales are not nearly as pleasant as the myth, Robin Hood (if he existed) may well of robbed the poor and committed some serious murder and other crimes Disney certainly wouldn't of added to their foxy take on the tale.
that's how I feel anyway, this is mythology for a reason - hook up in the history (real world) and every single hero is a monster.. likewise every single villain is a victim.. let's not focus then on the real-world history and rather on the stories and how they are remembered as a whole.