From time to time someone posts a comment updating, giving a different perspective or making a new point on an old post where it’s unlikely anyone else but me will find it. (This happened here yesterday).
At other times people want to comment on the blog in general or raise something not covered by a post.
That’s why I’ve created Your Page (under pages between Archives and Recent Posts on the side bar). It gives you the opportunity to do any or all of that; it’s your page, write what you like on it – within the bounds of decency and without defaming anyone.