The subtext of many of the responses to this post is a self-congratulatory "I knew all along that his plan was unrealistic". It seems like the thing people like about the follow-up post is that they think it confirms their worldview.
If we actually listen to the original author instead of looking for confirmation of our own worldviews, the author tells a different story. He says, (this is a copy-paste quote): "The initial plan itself was fine." His original plan wasn't unrealistic, at least not any more unrealistic than any more traditional life plans--it simply fell prey to life events which would cause almost any plan to fail. His partner left him for another man and he was diagnosed with a serious medical issue.
And critically, while the author's plan has changed, the goals still haven't. Not working is still the goal.
I've seen the plan that's common on Hacker News fail too. Lots of startups fail, and even if your startup succeeds that doesn't mean you're satisfied. The best case scenario has nothing to do with economics: it's coming to peace with yourself, finding meaningful relationships, and feeling a sense of purpose and belonging. I won't write off the possibility of finding those things in a startup or a career, but in my life I've seen it far less than the self-congratulatory posts here would lead you to believe.