The reasons and arguments put forward in the Encyclical may certainly be discussed, weighed, debated. The Pope's obvious intention is to decide a controversy which casts doubt on traditional teaching which has for centuries been approved by the magisterium. This conclusion is founded, in the eyes of all the Church's children, on a certainty of a spiritual and evangelical order. It is in the light of the Gospel, and helped by the Spirit which Jesus promised to him, that the Pope has recalled the basic laws of human sexuality as collaborator in the divine work of creation. He has said what is the Church's teaching on sex, marriage, contraception, childbirth.
Nothing is new.
Sin is sin just as night is dark. It is sin which is hateful. And those who are against the Encyclical love sin. They love sin so much that they clamour for it to be legalised, to be declared virtue. The Church hears sins in confession.