http://rorate-caeli.blogspot.com/2013/07/a-stunning-mea-culpa-regarding-sspx.html

‘The devil you know is better than the devil you don’t know’ but SSPX continues to have ties with the devil they know, his minions, his works, his chaotic ideals.  SSPX gives the devil total control over their ‘society’ allowing him to play mind games with it’s members.  The object is to divide and conquer.  Putting discord among the members, making them (even the stable and firm members) question if they were actually admonished of their sins and if they are living in sin once married.

If they were to cut the umbilical cord with Rome and acknowledge that the ‘Seat is Vacant’ they can just swat them away like a single gnat.  But now, SSPX will be swatting gnats of ideas that will be gnawing on the hearts and souls of their members.