The question is: when some U.S. bishops are at least as disobedient to Rome as SSPX, what makes one schismatic and the other not? Granted, there was a formal document regarding SSPX...this is more of a philosophical question.
Then consider the subject matter: one wishes to celebrate a particular version of the valid Roman Rite, without proper permission. The other apparently wishes to downplay a central teaching of the Church. Which is worse?
This is not to accuse all U.S. bishops of schism...it is simply to say that we have at least a few, and possibly more than a few, who are not doing their job.
The latter of course -- until the former group moved to consecrate its own bishops. It's that act of overt schism that placed the SSPX on a level every bit as bad as the worst of the AmChurch trimmers. This is not to impugn their love and reverence for the Trad rite, which it's well know I prefer myself. Their undoing as I hope you'll agree is in refusing to accept the humiliation and suffering that sometimes accompany obedience. To reject this mystery of suffering seems spiritually defective.