They have all sorts of modern features more conducive to discussion and community-building like notifications that someone @mention/replied to you and even editing your post -- features that people generally like. If you don't think that's "fun", fair enough, but I also enumerated other benefits like their broader appeal.

Any community that only has a mailing list could benefit from experimenting with a proper forum. I've seen this experiment broaden a community time and time again as you move away from only selecting for the type of person who likes mailing lists. And notice that HN isn't a mailing list either.

For example, I would imagine that the sort of people interested in high-quality ebooks extend beyond mailing list loving super-techies. Even a subreddit would be a nice option.

My question was simply about how much fun you experience using modern forums. I have never edited a post and thought it was fun.

Some people might say it's useful and others might say it encourages people to comment first and possibly focus on polishing the comment second.

For start... they aren't a freaking mailing list?

E-mail sucks.