SPPX (with apologies to St. Pius) are not coming back. They say the church hierarchy has sworn allegience to Satan, the Cathechism of the Catholic church is overflowing with heresies and the church has delibertly distorted and taught heresies (such as NFP and the correct understanding of no salvation outside of the Church). And that's just the mainstream ones. Why would they come back?
Then there's folks like Williamson and Tissier de Mallaraise. Williamson has been delivering gems for years now, such as it is a sin for women to wear pants and women are not capable of higher learing.
http://www.sspx.ca/Documents/Bishop-Williamson/September1-2001.htm He also blames the government for 9/11, Oklahoma City and Pearl Harbor. http://sspx.ca/Documents/Bishop-Williamson/September1-2002.htm
Tissier claims that not one Jew perished in the gas chambers of Hitler. http://jloughnan.tripod.com/sparwill.htm
These guys belong at DU, they won't be comfortable in full communion with Rome. They are filled with way too much hate and anger. They're not coming back.
and yet they are so like the Black Knight...
Fellay: Oh? All right, we'll call it a draw.
Pope:Come, Archbishop Bertone
Patsy. Fellay:Oh. Oh, I see. Running away, eh? You yellow bastards! Come back here and take what's coming to you. I'll bite your legs off!
*Remember the Iron Law of schisms, "They grow by leaps and bounds."
Who are you to claim a schism isn't a result of the Triune God defending His Church. Don't you know that Tradition teaches schisms preserve the truth which the Church Jesus established tries, from time to time, to destroy. If it weren't for this most recent schism, Holy Mother Church would perish. Get with it man :)
Apart from their antisemitism; their hatred of the Living Msgisterium; their hatred of the most recent Ecumenical council; and their hatred of the normative Mass, I don't really know what attracts their followers :)