One way I know that the 'resistance' is wrong ...
... is in their decision to not attend an un-compromised Catholic Mass on Sundays.
I have friends who have made this decision, and I fear for them ... on a number of levels.
First, their own souls.
It is still a precept of the Church to attend Mass on Sundays and Holy Days of obligation (however few these may be). To decide, when there is no danger to the faith, to no attend Mass is a mortal sin. These people know better and I think that this is one of the ways that the Devil keeps them in this state.
Second, the souls of their children.
What example is being given to their children? How will they internalize this decision (let alone the fantasies that are put out by the 'resistance' priests who periodically visit) and use it as a guide for their lives when they are adults?
Third, the souls of the priests that they are supporting in their error.
These priests have given the ability to continue it their error without cause for reflection. Humble reflection is what they need and it will only be with humility that they would be able to rejoin and contribute to the work of Archbishop Lefebvre.
Pray for them and pray for patience because they are an example (just the latest in a series) of what can happen when one strays from the path of the Church.