At a higher level, I disagree with your point that you can get away without the "hassle" of promoting your content. You'll always have to do some kind of promotion of your content, even if it's really good. And, if it's bad, no amount of promotion will get it anywhere.
IMHO, the main point I'm driving at is that there is no "free lunch". You'll always have to promote your content in order to gain a followship. It's just a fact of the web.
Regarding your point about this not completely eliminating the promotional aspect of gaining a followship, that's not what Phrot is ultimately about. I agree if you really want a followship, you do have to work hard to build it up, and if you're publishing content on a daily basis, that's not what Phrot is for, you can use a wordpress blog or something similar for that. I should also make it clear that we're all about promoting and rewarding good content that wouldn't otherwise be discovered, not giving a chance in the spotlight to everything that gets submitted regardless of how good or bad it is.
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 :).