Dare Obasanjo nails it. Blogs are the 'worse is better' of publishing. Sure, most them have mangled HTML, sure, most of them have brain dead RSS files. Sure, most them are ugly. But the 1% Gold amongst all the the other stuff makes blogging worthwhile and compelling. And why do we have that gold? Because blogs make it easy to publish stuff. Still not easy enough for my mother but we are getting there!
I find Joel's perspective interesting. First of all, I seriously doubt that Microsoft could ever get to the point where 100% of its employees were blogging. Secondly, he makes it seem that blogging doesn't provide value to Microsoft and it is a mere waste of time. This is very, very far from the truth. Besides the abstract benefits such as the fact that it “humanizes” Microsoft to developers there are many practical benefits which we provide to our customers.
Up until blogging, the only channels for getting technical information to our customers were press releases, articles on MSDN or Knowledge Base articles. That is a fairly high barrier to getting information that people working with Microsoft software need to get their jobs done. It isn't like this information doesn't exist. Daily there are hundreds of emails full of information about the inner workings of some component, the roadmap for some technology or the work around flying around the internal aliases at Microsoft that our customers never get to see but would be amazingly useful to them. Take Raymond Chen's blog as an example of this. About 3 years ago when I interned at Microsoft I stumbled on his internal web page that contained all sorts of interesting, useful and technical anecdotes about the history of Windows programming. Up until blogging, useful information such as What order do programs in the startup group execute?, Why are HANDLE return values so inconsistent? , or Why can't the system hibernate just one process? simply languished as information that was only privy to the folks who happened to be on the right email distribution lists at Microsoft or stumbled on the right internal website. Raymond's blog isn't the only one like this, just today I've seen Don Box post about the roadmap for .NET Remoting, Omar Shahine has a post on the issues with building .NET Framework components as addins to Outlook and Philo Janus on implementing context sensitive Help in InfoPath.
Would our customers have access to this wealth of information if we restricted ourselves to traditional channels of communication (press releases, white papers, KB articles, etc)? I don't think so. I do agree that like most things there are high quality blogs from Microsoft employees and others that aren't as useful. But that's life, 99% of everything is crap.