I am not a webdev either. This is a trivial CSS indeed. I don't think you are missing anything. When I posted this on Hacker News, I was hoping some people would like it because they might find it useful. Like I said, I am not really a front-end developer. But I do hack up simple HTML pages together for simple text-based websites from time to time. While doing so, I find myself using this minimal (and trivial) CSS frequently to make the page appear slightly more pleasing compared to what it looks like with the browser defaults, so I moved all that CSS out to a separate repository and shared it here. It is useful to me. If it is useful to someone else, that's a bonus!
I beg to disagree. Having browsed quite a few sites with css disabled over the years, I can assess that default stylesheets tend to grow in you and that you may end up liking them.
In a saner world, all sites would use default stylesheets (with empty css), and individual users would set up whatever css they deem beautiful each day.
The motivation comes from other CSS frameworks which have thousands of lines and due to the inheriting structure of CSS can be a challenge to integrate or update in existing projects.