If the church can last three years without a pope, who is to say that the interregnum cannot last ten, twenty, or even seventy years. There is not some magical formula, "Well three years we can do, seventy years we cannot do."
And my question is, why does John Paul II get dethroned from the papacy for supporting the New Mass and ecuмenism, but Siri does not? Once again, Card. Siri did nothing to blast the NO, nothing to defend his "papacy," and what evidence is there to the contrary?
I often wonder what would have happened if Pius XII put a statue of Buddha on top of the tabernacle, what would have the Catholics said? Because he would have been a validly elected pontiff, who, committing a sacrilegious action, would have given grave scandal to the Church. This is the case of JPII at Assisi. And once again, a good number of the cardinals who elected JPII were valid cardinals even by sedevacantist standards.
And I am not so sure that a pope loses his pontificate because he has a positive desire to destroy the Church. The head of any other entity, the family, a business - any entity that comes to mind- can have a desire to destroy that entity, while still remaining its head.