Because at that time, The pathway to Lusittiana was a territory conquered by the Germans troop during their conflict with Great Britain in World War I. The Germans give the warning following the international law of warfare at that time that indicates each nations should give warning to normal civilians if they intended to target a certain area.
Columbus did not have a respectful opinion of the Americans, and he only cared about finding riches. He did not view the American Indians as a threat, so he treated them badly.
