A lot of people just want to write something without having to spend time marketing it. It doesn't make sense, why would you want to do that, when all you want to do is write one or two blog posts in a year? Phrot is a very community centric site to blog with. It's designed for the person that wants to write about something, and wants it to be read, but doesn't want to have to go through all the hassle of promoting it.
This isn't designed to replace other blogging platforms like wordpress, just to provide a more suitable alternative for people who want to do things a bit differently. I hope this answers your question :).