Rejected by whom? By the Arabs because of the Catholic outreach of the council to Jews and their new Jewish state;
By the Jews because they had their new state, with visions of the 3rd temple dancing in their heads (and for the anti-semetic nature still in
some of the Church);
By the Orthodox who would not budge on Papal authority;
By European Protestants still resenting the Jews.
By American Protestants who were just starting to roll in the money-
and deeply inspired by the Catholic/Protestant divide this would afford them.
The Council failed on the global scale because no one wanted unity.
John23 over-estimated a war ravaged world in this desire.
The new Pentecost was to be for the entire world-
But as we would learn - they did not - and still do not - want one.