The SSPX is vicious in it's attacks on the post Vatican II Papacy, from Pope John XXIII right up to Pope Benedict XVI, especially on those Popes who extended to the SSPX for reconciliation. They do not believe these Popes are legitimate, just like Protestants! I guess they do not under stand that the Holy Spirit guides the Church, and Vatican II was meant to come about. "The gates of hell shall not prevail against it".
The day will come when the SSPX leadership stands before Saint Peter, and I can imagine him asking of them, "So, why did YOU break from the Catholic Church?". All the while St. Peter is dangling the keys before them.
I suppose you could say that about a lot of regular parishes in our country. They're just a little more quiet about it...