Same way there being factors in a country for example that raise the occurance of alcoholism and cigarette use still means each of the people individually do have responsibilites to stop smoking. Or how crime rates are higher in poor places still means that violent crime(not the one where people steal basic needs) is still the responsibility of the individual. You have to look at the greater picture and the individuals at the same time. Also i dont know who said it first but to paraphrase my mom “At some point you have to responsible for your actions”. Most places in the world draw this line from 12 to 21 but often different kinds of responsibilites come at different times.