The idea is that you can write your blog posts in your favorite coding editor instead of some web form. Some people find that easier - I certainly feel more at home in my editor.
Hell, if you were a real hacker, you would ssh to your server with vim or emacs, write the post in markdown or somesuch, and have your the blosxom-inspired clone you wrote yourself serve up the HTML.
The real reason it's "for hackers" is for marketing. That and improving its chances for a front-page mention here.
The real reason it's for hackers is that it uses Git and the command line to manage it. It may not be "hack-ery" enough for you, but it's certainly not software non-hackers are going to use.
Funny and deserved an upvote, but in reality I bet hackers are more willing to invest in tools they find good. Still, it wouldn't describe the market size of course, but the worthiness of pursuing it.
That's the idea of Jekyll, which is what this is based on. Doesn't explain what makes this a "blogging framework for hackers" (other than their choice of using Jekyll).
That's how I always used Wordpress, but it's not exactly elegant. You always have to make little edits in a small textarea box. No syntax highlighting. Need to submit the entire article to save (instead of command-s). You lose your cursor position when you save (super-annoying with longer posts). Wordpress doesn't support markdown natively. etc.
The real reason it's "for hackers" is for marketing. That and improving its chances for a front-page mention here.