Many people dislike CAPTCHA as a part of form submit policy. Indeed this thing so-called CAPTCHA gave a better security improvement when we apply it, but it doesn’t give a nicer user experience since CAPTCHA pushes someone to read it correctly when it makes itself harder to read properly.
But somehow, I just don’t thing to use CAPTCHA only for security reason. CAPTCHA can lowering comments rate on many pages/posts, including the old and the new one.
Why someone would want that? Well, if you have not much time to manage a blog or two, and you didn’t wish to close the comment forms, I think CAPTCHA would help greatly.
Even you write many posts/articles once a time – since you love to write obviously, has tons of archives already. But with this methods, the comment rate would always stays as lower as possible, so you don’t have to manage it so often. And saving a lot of time in the future now.