I think this is a general problem with online discussion. You can have more productive discussion about capitalism/socialism/anarchism in a bar in the deep south than you can online. Online people tend to forget there’s another person with a brain on the other side of the conversation (if they even intended to be having a conversation, which people mostly don’t). We know from every day life that people don’t speak carefully in conversation—you really have to be constantly extending the benefit of the doubt. Online no one extends the benefit of the doubt even though we know most comments are off the cuff on the toilet.
There are some neat online tools for structuring discussions like Kialo that I think make some headway in diminishing the effect, but drinking a beer with someone while discussing still works better as far as having an interlocutor who is actually considering what you’re saying and who might actually be willing to shift their own view.
Internet is better equipped for quippy one liners and getting (bastardized) ideas into the zeitgeist.