Also note that in the lesson "intent to kill" is not presented by Quirrel as purely good thing, nor is Harry called the most capable warrior or the best kid to have your back in the fight but the most dangerous student, an epithet that could well apply to the cadet with the worst trigger discipline. It appears that intent to kill goes along with a lack of squeamishness about violence, and it may be easier to teach Harry about the proper uses of violence than to train Draco to be unaffected by it, but that does not mean that intent to kill is itself a good thing