Usually blogs don't require creating an account to leave comments. Why present this false alternative when the common thing to do is just leaving a comment without creating an account?
why would you need to create an account to leave a comment? the site owner can own the entire flow if they so wish, including creating an anonymous actor for the comment.
Even back before 2010, almost all blogging platforms had an option that would let the owner require log in to comment.
And it was fairly common, because of spam.