This is something that always amazes and irritates a convert like myself. I have to think that these dissidents are either gutless, dishonest or dillusional. To be the most charitable, maybe they are just plain ignorant, but it is hard to imagine how that is possible in this age of information.
Perhaps gutless because they haven’t the courage to leave when they know their views are no longer Catholic in the most critical way.
Perhaps dishonest because they know they are defying Church teaching and teaching authority but do it anyway under the name of Catholic.
Perhaps dillusional in thinking that defying Church teaching will somehow result in seeing that teaching changed to suit them.
Some seem even malicious and bent on destroying the Church by misrepresentation. It is hard to figure them out, particularly for someone who has consciously chosen to affirm the teaching of the Catholic Church, has chosen to submit to the authority of the Catholic Church given by Jesus Christ himself. There was a time when I could have become anything I wanted, a Lutheran, a Methodist, an Anglican, all of which I considered in my journey to the Catholic Church, but was compelled by the truth to be Catholic, frankly the last place I intended to end up. So when I see someone essentially spit in the eye of Holy Mother Church and claim to be one of her children, I am alternately dumbfounded and outraged.
Technically speaking, however, if they are baptized Catholics that mark stays on them throughout their life and into the afterlife, wherever they wind up in the end. And, unless they formally renounce the Catholic Church they are still Catholics, whether or not they are in communion. The door is always left open for repentance, forgiveness and reconciliation, which is as it should be, for that is the will of Christ.
But it would be nice if they were honest enough to identify themselves as dissidents at least. My Baptist family would say that is what you get for baptizing infants and in a way that is always a risk, because everyone has free will when they are old enough to exercise it. But I am inclined to think that formation and catechesis are just as critical in most cases, so that if a Catholic at one point decides to dissent, it will have been based on complete information, an informed decision, as it were.