The poster did not say what is being claimed they said.
Are you referring to post #33 by redhawk.44mag?
redhawk.44mag: “I agree it’s not ok, but I also do not think it will ruin well-mannered college kids.”
I reread the thread and that’s the closest I can find that says kids aren’t harmed by porn. Was that it? If so, I agree the poster wasn’t talking about children. College “kids” aren’t children.
On the other hand, I don’t agree with the post. As I wrote previously, being well mannered probably has nothing to do with one becoming addicted to porn or having unrealistic expectations created by porn. If the latter is true—and I think it is—it might make real sex less fulfilling for that person.