Eh, Bale's Batman might not have killed but he did stuff comic book Batman would never do like when he left Ra's on that train to die. Comic Batman goes out of his way to save lives no matter who it is even if it's at the risk to himself, for anyone civillian, hero or villain. He's even gone out of his way to save the Joker, so Baleman isn't the best judge of how a movie Batman should behave imo.
You're right that people are easier on movies they like but I guess I'll never be able to get behind they way of thinking, it just doesn't make sense to me. If Batman killing is so horrible and OOC to some people then they need to stand behind that argument no matter what whether the Batman that's killing is in a good movie or not.