A hater of mankind? That is a very narrow understanding of Nietzsche. First, it is not a question of hate but of contempt. Nietzsche holds man in contempt in so far as he is content, i.e., happy to be "true to his nature". Also, Nietzsche did not think that "mankind" as a whole existed. He thought that what mattered was not the species, not the human race, but its highest exemplars - he would gladly sacrifice the greatest part of humanity for these individuals. Not that that would be the way, as "the many" constitute the soil, the dungheap from which these rare flowers may grow; but if it would further the latter, he would sacrifice the former without remorse. So Nietzsche's "hate of mankind" is really contempt of the many - the reverse side of his love of the few. The essence of his position, therefore, is love. And, as all love, it is love for his ideal, which he sees reflected in certain exceptional individuals, families, tribes, and even peoples.