I'd say that largely depends upon the content. For the content in the original post, I'd generally agree that there isn't likely a huge audience. For some niche

I'd say that largely depends upon the content. For the content in the original post, I'd generally agree that there isn't likely a huge audience. For some niche (often technical) topics/articles however, the content can be a very valuable resource to interested readers. Additionally, writing blogs/or blog like articles on one's own site doesn't necessarily have to be directed at growing an audience. I personally think that adding some formality to writing (which might not exist in a diary) and publishing it can produce some useful notes for the author to reflect upon later. If nothing else writing short articles can serve as useful practice in writing down and expressing ideas. Of course there is still plenty to be said about the benefits of pen and paper which people do seem to overlook.