Good question, though upon occasion there is a little bit of it that I've seen on this forum.
The growing dislike of Bergoglio is likely part of why we're not seeing knock-down drag-outs between the factions? Or is that serving more simply to embolden the "sed's"?
What I don't get, is how in the heck a sedevacantist could imagine there is still God's own guidance there, yet not see that the exceptions and qualifiers to the idea that the Lord would 'not allow the Church to fall into error' would apply at least theoretically 10,000% just as well among nominally Protestant congregations, as it would themselves, and almost anybody...albeit mileage (and velocity, too) would vary.
Yeah, let me know if you get anything remotely sounding like an explanation for this. The “Jesus let Judas into the group” excuse just doesn’t cut it.