Pride will do that. It kills, all around it too. Some go through life without ever being completely broken and by way of avoiding such trials pride and entitlement take root and go deep. Once that happens a person is capable of justifying any and everything, even to the point of destroying others. I know people who have never faced brokenness and instead have achieved temporal success through cleverness, but in the end they will always be wanting. There must be humility to be truly human.