Agreed: my comment should not be the top comment; it's just one small critique. I just see this so frequently (low low contrast, hard to read text) as well as other accessibility issues on sites linked from hn that I started griping about it. FWIW I don't just gripe about it, sometimes I actually do something: https://github.com/addyosmani/todomvc/pull/37 :)
In the end I think it's important to remember that even if the content is the best thing in the world, that doesn't mean much if people can't read it. I'm probably just a curmudgeon but I've clicked links to posts where I saw the contrast and size and said "I'm not going to bother reading this. It is too hard and I don't care enough about this article to change my browser settings to correct the designer's mistakes." And many people don't have the skills to do so. Three cheers for agreement! :)
Sincerely, it wasn't a personal attack. I am just sad a short comment about the look & feel make the top instead of a comment about the content.
Even if in the end, I tend to agree with you that this color contrast is a design error.
ps: Also, if you visit my website, you will see I am fully aware of accessibility and try to take a good care about it.