I think home-grown blog software nicely illustrates the fact that public pressure and users actually and significantly improve the quality of a given software. (And I am not saying that you don't understand this, btw. I am sure you do.) There rarely is anything too demanding to implement in a blog software, but the sheer amount of features you need to implement is overwhelming. Implementing your own blog software starts with the usual "I can do this myself" and ends with "I am tired of implementing yet another must-have feature."