There's a problems with this sort of blog post. It's a survivor story. The author severed the links to his old life, put everything in to his startup, and came through it successfully. But that's only one data point. There are
thousands of people who have done the exact same thing and failed, and deeply regretted severing those ties. Equally, there are plenty of stories of people who didn't cut their ties to their old lives and gone on to be successful (Mark Zuckerberg being a good example - many of the first hires at FB were his friends). Consequently you can't really learn anything from it. You can't tell ahead of time whether or not cutting ties is a good idea. The implication is "If you don't cut the ties to your old life you will fail!", but that just isn't true. Even if you're more generous and read it as "If you cut the ties to your old life you're more likely to succeed" that (probably) isn't true either - having ties to things outside of your startup doesn't have a big impact compared to some of the other, much more important things (cash, market, product, etc).
It's a great story of how one founder refused to quit and created something amazing, but that's all. As a lesson in how to succeed in your startup it's not really telling you anything at all.