I am of the opinion that among sedevacantists, there is some mental block which prohibits them from accepting fact, much like sedevacantist McCork's promoting of some faith in these forums which is not Catholic, regardless that he insists otherwise, even after being corrected numerous times.
Because OCAC is proven to be true using only elementary and fundamental Catholic teaching, the sedes cannot claim the pope, being ipso facto excommunicated due to his heresies, is no longer Catholic therefore no longer pope. This is not acceptable to them to the point of saying Trent was wrong.
We see here demonstrated by Desmond yet again where one cannot use Church teaching to vindicate sedevacantism. There is no Church teaching that teaches, or in any way supports sedevacantism, it is in fact just the opposite, as this thread testifies.