"Show HN: I showed up at work and did nothing else this week"
or
"Shown HN: I read some blog posts and a chapter of a book today"
or
"Show HN: I followed the tutorial for this language/framework"
or
"Show HN: I had an idea to build something but I gave up after the 1st weekend working on it"
then you would get a much different picture of the distribution of users with actual side projects.