I imagine most HN people do know that Jekyll is a static blog generator written in Ruby, which is used by Github pages. However, he has a point that I often up on open source release announcements, and I don't know what the project is about, and there isn't an obvious link to the that information.
It's really advice to the coder on spreading word about your project. If you want people to dig into it, help them. Don't make them go on a wild goose chase figuring out what the thing is in the first place. If you don't have a reason to care about something in the first few seconds, you'll move along and look at something else that is shiny.
It hasn't really. Google doesn't read code and summarize purpose yet...that still requires people who understand to convey they message to those that don't.
I do know what it is; I also know what Jenkins, Jakarta, Jellyfish and Jasper are.
There is literally nothing in the text of the linked page to provide enough context for those of us who are familiar with projects but bad with names to decipher which one of the thousands of projects we've seen announced or discussed it is about.
Jekyll is one of hundreds of projects that popped up in the Great Static Site Generator Rush of 2012, so I think asking for a blurb is reasonable.