Comment systems have grown into ubiquity over the years, from the most basic blog comments to integration with large ecosystems like Facebook and Instagram. They're a much simpler and direct form of communication than a full discussion forum, and this has pros and cons. It's much easier to engage a user into leaving a brief comment than to invest more into a forum discussion, but this is a double-edged sword. "Don't read the comments" is a common Internet meme, because the quick nature of comment systems often appeals to users who don't want to contribute much more than noise.

Quality communities based solely on comment systems do exist, but they require care, moderation and work. Simply adding comments to your content and forgetting about it will lead to problems down the line.