If the entire point of creating a blog is to talk about yourself, or to get people talking about you or the things you care about, then it matters what judgments people have formed about the particular blog tool you use. Traditionally, for instance, LiveJournal has been a place of closely connected teenagers; you could try, if you wanted, to publish your well-researched foreign policy musings on an LJ blog, but chances are not many people are going to take you seriously.
Farhad Manjoo wrote an article about the history Six Apart for Salon. I never realized that the events of September 11, 2001 made Mena think that blogging was a bit trivial. I feel the opposite is true. When a major event happens people are looking for an outlet. Craig’s List was full of postings from people coping with what just happened. My relatives in Ireland wanted to know how we were reacting and what changed. Everyone was watching and listening for the latest news.