He has always been ruthless and cold and cruel even when he hasn't been, if that makes any sense. Hermione thinks he can't help it – it's part of him, in his nature, the way he was raised, and every time that he is kind, or thoughtful, or compassionate, he is defying his nature. It is not natural for him to care for others who are not of his blood. But there is a seed inside Draco that his upbringing could not crush out of him – the thing that stopped him from killing Dumbledore, that night on top of the astronomy tower. The seed of humanity that stayed his hand, and made him waver in his resolve to murder the Hogwarts Headmaster.