@Lisi Sterndorfer J a und weil die FSSPX nicht Eins mit solchen Gruppen und Kirchen sein will ist sie Schismatisch aus römischer Sicht

To put the controversy in perspective, it is helpful to review the thinking of Rome just a few years back:
“I am of the opinion, to be sure, that the old rite should be granted much more generously to all those who desire it. It’s impossible to see what could be dangerous or unacceptable about that. A community [i.e. Rome] is calling its very being into question when it suddenly declares that what until now was its holiest and highest possession is strictly forbidden and when it makes the longing for it seem downright indecent.” (Ratzinger Salt of the Earth (1997)
If these are the thoughts of the Prefect of the Congregation for the Doctrine of the Faith (future Pope Benedict XVI) it is not possible to hold that the SSPX is schismatic for holding the same beliefs and striving to preserve "the holiest and highest possession".
The author states up-front, that his only interaction with the SSPX are acquaintances and students. The treatment of the controversy would be more balanced after a study of the history of the SSPX and the principles of the Society.
The SSPX is simply forming priests who will follow the faith and morals of the pre-vatican II Catholic Church and serve the faithful who likewise cling to that faith and those morals. That is its sole purpose. It recognizes the Pope and the hierarchy in all aspects where they do not contradict that purpose.
From that basis, it is clear that Rome is asking the faithful to abandon any attachment to that Apostolic Faith, e.g. we are one with the Anglicans (and Lutherans, Baptists, Muslims, Hindus, Buddhists, animists, atheists, materialist, etc.), humans have infinite dignity, reverence in worship is to be minimized, situational ethics is not only acceptable but superior to the Catholic ethics of 1,900 years, etc.
The SSPX, like the saints and martyrs before them, really has no choice but to continue in the Apostolic faith.

Pope Leo recently stood shoulder to shoulder with representatives of schismatic churches, celebrated vespers together, and proclaimed "We are one! We already are!" Among these schismatics to whom the pope spoke were the Armenian Apostolic Orthodox, who are non-Chalcedonian and don't even accept the two natures of Christ. If such a generous and accommodating attitude can be shown to schismatics who literally reject one of the seven ancient councils, there is absolutely room for a very generous attitude towards the Society at every level of the Church—even if we granted the Society is in schism. Even if you disagree with the Society, why can we not adopt the attitude modeled by Leo in his meeting with other Christian schismatics, whose schisms are much bigger, older, and graver? Would you be willing to stand with the SSPX and say "We are one! We already are!" If you aren't, then either you are off or Rome is.

Essentially, the Society has begun treating reconciliation with Rome the way Rome treats reconciliation with the Protestants.