8-12 years of child rearing is very expensive. That's without even taking into compounding returns from working longer hours, seniority, experience, and investments.
The blog post starts with your same premise: pull out all the stops on working hard. It's just a choice. Why not have a startup that takes longer to grow?
To make the point clear: children raised by young and growing parents and different from children raised by old and established parents. Slow startups are different from fast startups. No judgement, they are just different. But the premise that a fast startup is the only way to do a startup is false. It's just choices for different outcomes.
I am the child of two young parents who had to drop out of college to raise me and my siblings, eventually on my father's "lifestyle business" when working multiple jobs didn't balance the books, so I am well aware of the tradeoffs. In my experience though it's not a question of just adjusting your lifestyle for many people, it's a question of financial survival.
My parents have not come close to being financially recovered relative to later-parents a decade after we've all left the house. The delay you are talking about compounds to absolutely massive differences in my experience. Trying to multi-task both the other "life" check boxes and your work is going to have large hidden costs on work because of these compounding advantages.
