These folks are the people who could use some evangelization, but if any one of us were to join and start posting the Truth in there, we would be banned in a New York minute.
Well, I suppose one could survive with heavy self-censorship.
And sneak in bits of truth stealthily by feigning innocence and ignorance, like :
"Oh, but I read in XXX encyclical that... "
"How do you reconcile that with XXX ?"
"My traditionalist cousin told me ZZZ! How can this be???"
Of course that would be morally grey if not outright deceitful probably.
Probably almost entirely fruitless too, as I've seen past Doctrine and even Popes and even God (!!!!) being condemned as "intolerant" or "uncharitable" "erroneous" with ease in that cesspit of a forum.
What about, pm'ing the people more obviously in spiritual pain, inviting them to an honest discussion about their issues?
And quite sad.
The desperation and frustration from the converts transpires from their comments... here's people who thought they were joining the One True Church, often with significant personal/social difficulty, and just now start realising they've just plunged in a nightmarish cage of doublethink, vileness and insanity.