Gabor has a post here where he points out that the level of interaction is lower than the other blogs, he mentions blogs.perl.org and chromatic's blog as an example.
On more than one occasion I have typed in my comment only to realize that you need to be logged in to comment ( Gabor's , blogs.perl.org and chromatic's blog all require login) . I understand spam is a issue but if you want me to login to comment I will most probably not do it .