I'm not sure you are correct, I began teaching my little sister the most basic forms of programming a few months ago, she's 9 and now she can easily form and use arrays, functions, database loops and simple OOP.
She isn't anywhere near what I would consider a "good" programmer, but she is capable and for her age her intelligence level is phenomenal.
this is great, but it says nothing about how likely a 0-10 year old would be to find the content on hn interesting for any period of time.
it's pretty obvious people are either unable to read, or more likely deliberately trying to skew the results. There will always be those that try to break things, the ones that were likely bullies in high school, didn't get laid in college and are now bored and discontented in their jobs. it's a fraction of every group, but always present.
In my opinion starting programming at a young age is almost orthogonal to being interested in HN links and discussions from a young age, mostly because kids have other interests than adults, even if they like programming.
I'm not saying that there aren't any children reading HN btw.
I'm fifteen and have been reading HN for more than a year now, and I would have to agree. The content on HN is interesting for those who intend to make a career out of technology, not necessarily those who program solely because it's fun.