Blogs and Bloggers.

I really cannot understand why some people set up a Blog, then make comments that they know are controversial, and when they get comments that do not agree with them they remove them from the comment section.
What is the problem? If you want to talk to your self, and are not interested in the thoughts of others, why don't you just go out to the front porch and sit and talk to your self. What do you others think?