However, at the end of the day, you are taking a risk, it's a gamble. What stops most people is the fear of failure. This fear isn't necessarily unwarranted. As the author points out, he has a previous failed startup. Most people don't have the drive to work hundreds of hours after work and possibly invest their own hard earned cash in a project they suspect deep down might not actually pan out. I know I find it difficult.
Still, I don't dislike these stories. It's good if it inspires people to take (calculated) risks, and it is possible to learn from failures. Though I would also say that yeah, there's probably some self-selection going on. The people out there with 2 or 3 failed attempts at monetizing side-projects probably don't feel super eager to write a blog post and tell us all how we can improve our lives by following in their footsteps.