The whole situation with the nuns, you know what this thread is supposed to be about, was unfortunate.
The number one factor was emotion and feelings. Pictures, images, situations etc. made the nuns feel a certain way. The nuns who left were mostly the touchy-feely types.
Another factor was that there had never been a problem of this type before, so there were really no rules or boundaries regarding theological positions, as differences in the ranks were very peaceful before this fracture. The nuns grew up, as many of our own children might, in a Catholic bubble. Many had not really had much experience with the Novus Ordo and they were unaware of how traditionalism was perceived outside that bubble, mainly by the Novus Ordo sect. This is not necessarily the fault of the order but as result of their parents not understanding the issues or educating them regarding the situation in the Church. Talk to any traditionalist child or young adult who did not grow up in the Novus Ordo, or outside of it, and you will see a difference between "converts" and cradle "traditionalists."
Sometimes, I think that many mistakes or friendly errors (regarding policy, trust, non-doctrinal choices) are made within traditionalism by clergy and religious because they had a different upbringing and they don't have the cynicism? Or maybe experience? which many of us who searched and searched for the truth might have. I see it in my own children and so do my friends, what many of us have known as Catholics, the struggle, is foreign to them.
I think that they should not have met in secret with the Novus Ordo authorities. It was false and conniving. They wonder why they lost the trust of their former sisters? They were completely two-faced. If they were going to leave, their departure might have been more amiicable but it should have been conducted in an up-front manner. They have also made it clear that their intent, in all communications with the current sisters, would be to convert them to the conciliar sect, not to keep up friendships or maintain some odd form of unity as Catholics.