Allowing comments is a personal choice. Engaged and friendly comments act as a form of social proof encouraging others to likewise join in.
On the other hand, if you are confident that you produce as consistently good as Seth Godin and you don’t like moderating, perhaps comments are something you can opt out of.
A good reason to disable comments is because you have very limited time to maintain the back end of things like moderating comments and removing spam.
On the whole, I would say that comments encourage a community to develop which adds value. They are not for everyone and there is no one right or wrong answer.