Here is the issue:
The SSPX has fallen. That is the objective truth.
Various faithful, religious and clergy can react as they will to this -- but they will continuously bump up against this reality. Reality is a harsh mistress.
Just like some priests in the Novus Ordo wake up to Tradition slowly at first, trying to "have it both ways" and stay on good terms with their bishop and other Church authorities -- but eventually a situation arises, things come to a head, and they have to make a decisive choice. At that moment, they see the wisdom of those who have been there all along (Traditional Catholics, the Resistance, etc.) and hopefully they make the right decision -- to join them.
Eventually every single layman, religious and priest will have to choose between the Catholic Faith and the new Vatican II religion of man. Right now, that doesn't seem so obvious to many SSPX-attendees. Everything "seems" normal. It "seems" like they can have it both ways; seem to reject the Novus Ordo and still have their Tridentine Mass on Sunday. But ultimately, and before too long, each and every individual will be forced to choose. Some sooner than others.
Remember all those martyrs who were held at sword-point and forced to make a choice: burn a grain of incense to the false gods, or stay faithful to Christ and lose their life. Many individuals chose Christ, and many (who we have forgotten) chose to compromise and burn the incense. But think about it: for weeks and months (or even years) beforehand, they were able to have it both ways and attend their local Catacombs chapel for Mass, and still be on good terms with the Roman authorities. But eventually they were forced to choose...