Like children commenters said, comments are very useful if there's a community around your site. For my personal blog, comments were mostly "thanks" and sometimes angry comments about how I didn't like the thing they liked, although these were rare.

There were sometimes helpful corrections, but those came largely through email anyway, and, since I update the articles when I receive a correction, the corrective comments instantly became obsolete.

I just remembered the biggest reason why I removed comments: Spam. The added value wasn't significant enough (due to the reasons above) to warrant spending the time I spent removing span comments. Make a popular post and you'll get a whole bunch of "What a great post! Check out my thing: <thing>". I didn't want to spend more time moderating so I just disabled comments.