First time visitor to your site - and agree with your points - they are right on! The other piece I find of no value is when a user consistently updates via txt or a feed - it is merely a one-way relationship.
Scott, I launched my blog for many of the same reasons as others that have commented. In addition, I was looking for a platform to network with others and share best practices within the industry. There are several other blogs out there similar to mine, but most are doing it to "sell" a specific service in the end, and have recycled the same content over and over again.