Most bloggers see their blog as a means to open a discussion with others. Hence the "comments" feature.
Some bloggers, of course, prefer to turn comments off, and present their blog as a platform from which to express their thoughts. That is fine also.
What I don't understand, however, is bloggers who don't disable the comments, but who then don't allow you, for unspecified reasons, to leave a comment about any post.
One such blogger, apparently, is Luigi Muzii, of the interesting Italian blog "il barbaro".
Luigi, I would have liked to leave a few comments about some interesting posts of yours (including one in which you quote me), but when I try to enter comments on any post, I just get this: "Spiacente, non puoi commentare questo post!" ("Sorry, but you cannot lave a comment for this post!")