Commentary on top 10 blog usability mistakes - no author biographies

According to the top 10 blog usability mistakes list by Jakob Nielsen (2005) the readers of the blog want to know who are they dealing with and not having an author biography is one of the top 10 blog usability mistakes. But is it really a matter of trust? According to Nielsen signed writings have more credibility than anonymous writings. In my humble opinion facts and opinions speak for themselves and person behind them is rather inconsequential. We could draw a weak analogy to double blind peer-reviewed conference and journal papers. No one in their right mind (at least if they have some experience in research and publishing) would suggest that authors of submitted papers would also submit a detailed resume about their past and present work and publications for the reviewers to see if the results in that particular paper should be considered credible. Every submitted conference and journal paper must convince its peer-reviewers on its own merits, rather than the merits of its authors. And overall, having an author biography or not having one doesn't have very much to do with how the blog can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use, i.e. usability.