Jeff Atwood once said that "A blog without comments enabled is not a blog". I haven't been able to figure out if he's the orginator of this idea or not (mostly because I didn't look very hard), but there are a lot of articles that were published around that same date that seem to agree: if you have a blog, you must enable comments because the discussion is more valuable than the blog entry. You must have a way to have an open discussion between you, the author, and your audience because otherwise you're just a publisher, and publishing is boring. Being a publisher is not as great as maintaining a blog.
This is wrong.
I don't mean to pick on Jeff here (okay, maybe I do mean to pick a little bit), but there are a lot of people who share this idea. I think that the reason that they glom onto this idea is that somehow, somewhere it's been decided the most prized resource on the Internet is interactivity (this is actually not true, the real prized resource on the Internet is attention, but providing interactivity is an easy shortcut to gaining and keeping attention, so it's splitting hairs).
Since interactivity is the most prized resource on the Internet, lots of websites optimize for it, usually in the form of comment sections. Some of them are right there underneath every entry, some install forums, some outsource their comment sections to other sites (start up a tech blog, submit every story to Hacker News; start up a video game blog, submit every story to a video game subreddit; etc). Taking time to discuss every conceivable nuance of every morsel of information put on the Internet, has become the de facto way that the majority of people use the Internet.
Enabling comments means that you are inviting feedback on whatever it is you posted, which is fine if that's what you're after. But go to any comment section on any site on the Internet and you will very (very) rarely find anything useful or anything related to whatever the article was about (depending on how quickly topic drift happens). If the site is popular enough you might find a lot of comments, but you usually won't find much substance.
Writing is hard. Making videos is hard. Creating podcasts is hard.
Commenting is easy. Giving a 'like' is easy. Subscribing is easy.
If you create something, positive feedback feels good. Getting likes feels good. Getting positive comments feels good. Likes, views, and follower counts are the de facto currency of the Internet. They're how we measure how good something is. The more likes, views, and followers someone or something has, the better it must be.
Sites like Facebook, Twitter, and Reddit are examples of this. They're composed entirely of comments, and there are no topics. Facebook tries to give the illusion of topics by caling elevate comments as 'posts' that someone could follow or not, Reddit tries to give the illusion of topics with the Subreddit concept, but they're all giant comment sections carved up in different ways. There's usually no real content there. When you use these sites, you're not encouraged to make anything. You're encouraged to be the first to find something that someone else made and make a post about it so you can get the upvotes/likes/favorites. Making things is hard. Linking to a thing that someone else made is easy. Farming dopamine by being an intermediary between whoever made a thing and the people who might be interested in the thing is weird.
And I get it. Not everyone is willing or able to put in the time it takes to make a thing and put it in front of people. Sometimes you just want to consume something that someone else did. Or maybe you did take the time and did create something that you want to share, but you don't want to take the time, effort, and energy to set up and maintain a website just for the privilege of having a bored teenager fill up your comment section with racist garbage. There are lots of reasons why you might not want to have comments on your website.
Enabling comments on a blog (or any website) presupposes that the author of the blog is interested in a public dialogue. That might be true, but the opposite is true just as often. Sometimes I just want to say something to work out an issue or to get my knowledge organized to see where gaps are. Sometimes I want to do these things without worrying about anyone rushing to weigh in. If I want to engage in a discussion, I'll go to a forum, I'll go to email, I'll go to IRC.
A blog without comments is absolutely a blog. Once you start adding comment sections, it ceases to be a blog and it becomes a forum. It's a forum where the blog author is the only one allowed to make topics. I would go so far as to say that every site that allows comments is a forum. YouTube is a forum.
Turning every website into a forum increases the burden on the webmaster. Moderation has to happen. Deleting spam has to happen. And having forums everywhere puts forth the idea that it's expected and encouraged for everyone to react to everything as soon as possible. "Hit like, leave a comment, watch another video." Rinse and repeat.
I will continue calling my blog a blog. I will continue not having comments. If you want to discuss anything that I've written, that's great! I encourage you to do that. You'll just have to do it somewhere else.