At first, I didn't get it. Pingbacks, isn't that from the 90s? Then, I thought: does this mean the bar for joining a conversation on my publication is that you have to publish something too? That seems like a nice bar to set for asking both parties in a conversation to be fully engaged. Trolls seem like they will be too lazy to do that.
General reader responses are curated into a "Letters to the Editor" section, whereas the real discussion tended to happen between columnists in their respective columns.
That in contrast to what seems to be the popular misunderstanding—that columnists' opinion columns are summaries of an entire publication's political and philosophical stance.