Some clarification is needful.These 'needments' were so called to convey a sense of necessity and affirmation,but of course they are like banners ed on battlemements,symbolising power,but not telling the whole story of all which lies inside the citadel.Let us go to a clearing here in the forest-to your left you will see a small primitive altar.It is to a pagan god,but only portrays a rough phallos.This is because they dared not to represent the god in any full likeness.They knew,as we do,that life is in the main 'unintelligible'.This universe is not here to beseech our understanding;rather we have to use a consciousness that was evolved to aid the survival of a simian species in prehistory in order to achieve a dim comprehension of things beyond our ken.That 'morality' was evolved to help human survival in social groups is not seriously doubted today.The term 'moral' was originally intended as a synonym for the Greek 'ethos' [ethics];Cicero is usually credited with this.Now,however,'ethical' and 'moral' shade different meanings.'Ethos' means 'habit','custom',and so has a 'non-moral' sense [I agree that 'non-moral' is a better term than 'immoral',but is not Nietzschean,as I shall explain].In other words,moral no longer is the same as ethical,but is now meant in the sense of 'formal morality';i.e., a theory of a 'moral world',whether the creation of a posited god,or else a 'universal' moral truth.Nietzsche's moral philosophy was a 'metaethics',and viewed morality as an 'ethnoethics',a positive morality of the first type that I described,having only evolutionary significance.Nietzsche affirmed the ethics of the Noble;an ethics of the 'goodlife'['good' in the 'good bad' sense];an ethics which represent the 'character' of the excellent human being.Such an ethics is not an abstraction like formal morality.Somewhat confusingly Nietzsche called this 'master morality',when a 'master ethic' would have better contrasted with 'slave morality' [the latter is undoubtedly a 'morality' and not an ethic].So I agree that the term 'immoral',if taken out of context [and context is 'everything' with Nietzsche because we know that he deliberately eschewed technical terminology],does partake of morality.But then nor does 'amorality' [this is a 19th century neologism] in most senses.The best way to convey our view of the limited extent of moralism would be to oppose it with 'non-moral',or 'supra-moral'.Nietzsche used a similar construction in an early essay,but tended to use moral/ethical interchangeably for his mature works.I think this was because he knew that master morality was an 'ethnoethic';to a moralist it would be seen as 'immoral' and 'amoral' [all terms which carry moral disapprobation],but was in fact an ethical rule.So 'immoralism' is meant to convey opposition to formal morality,but still suggest that master morality is an ethic,albeit known as 'evil' to slaves.