I cannot speak for other posters here, but I personally have no grudge against the CMRI. I know the SSPX does not regard laity who attend CMRI chapels as non-Catholic or refused them Holy Communion when they ask. I do not doubt many Catholics, trying to make sense of these difficult times, may find in the CMRI a place of refuge from modern errors and liturgical heteropraxis. Also, in fairness, I have heard CMRI priests show very great zeal and devotion in caring for their faithful, so it is unsurprising that CMRI attendees here are likewise supportive of their priests from a charge they believe false. What is the measure of any traditional group at the end of the day? It comes down to how that group helps Catholic families to live a Catholic life in the modern world.
Personally, I would not attend a CMRI chapel, or encourage anyone to attend, for I don't agree with the position they officially endorse, which is 56+year sedevacantism. I also don't agree that the Church can be reduced to a state where pastors with the power of the keys, (which is given by Christ to Peter, that is the Pope, and from Peter comes to the Apostles, that is the bishops who receive a mission from him) cannot be found anymore, for the promise of Christ precludes that. If they agree with that, my advice to the CMRI would be to go to one such pastor, and receive their share in the power of the keys from him. The Pope receives from Christ the fullness of the power of the keys, which includes the power to give others a share in this power. A mere bishop, who only has a share in this power, does not have the power to transmit the keys to another, unless the Pope has delegated to him that power in the form of a Papal mandate. That is why the continuation of the Church depends on the Pope, and the Papacy is the foundation of the Roman Catholic Church. So, I would ask, how can it be that no one can be found in the Church today who can be relied upon to exercise this power, for the benefit of the CMRI priests? That brings us back to the impossibility of what 56+ year sedevacantism says has happened to the Catholic Church, in particular the ecclesia docens.
But, I would be wary in trying to judge anything more than that. I would say they do not have a right to claim ordinary jurisdiction, until they receive it from the Pope, or someone to whom the Pope has delegated it, and if they accept that, then I think going so far as to say the CMRI and those who attend are schismatic or non-Catholic is a judgment we should refrain from making.