That´s not my opinion. Essentialy, a) it was the revival of the old crusader dream. b) Also the concern over the Ottoman Turks - Spain lost Tunis and La Golleta in 1574, and the corsairs attacks on Algarve coast had increased; the golden opportunity occured when al-Mutawakkil was deposed by his uncle. We should keep in mind that the Portuguese Cortes even suggested closing of the University of Coimbra, transferring its funding to the Moroccan war effort. Sebastião revealed a personal obession with the revival of the neo reconquest in North Africa,and two years before the disaster, Sebastião paid visits to Ceuta and Tangier (1574)The Battle of Alcácer Quibir was not a conquest campaign to create a Portuguese Morocco
(Filipe of Spain did elicit un undertaking from Sebastão that if he mounted an expedition, he would direct it primarely against Larache, a Moroccan atlantic port, ideal base for corsair seeking to attack Spain)