I think there's some value if you're more interested in creating a lifestyle business than a unicorn (as it seems like we both are), but it's certainly not perfectly matched to that goal.
It's a shame there's not a Startup School-like resource for creating a lifestyle business (YC-like in that it'd have a unified theory of lifestyle business creation, as YC has for startups, that'd been honed through assisting in the creation of hundreds of such businesses).
There is. It's called Hacker News. There's isn't a better resource to learn more about starting a small business than HN itself. From starting a consulting business to creating a passive income, everything has been extensively discussed. There are tons of inspiring stories here about creating a small business. (Incidentally, I think it would a great idea to collect all entrepreneurship related threads in a single place.)
HN's expertise falls short when it comes to adjudicating unicorns as they don't usually look promising at the beginning. But, in case of a small product, I think community's feedback and advice can be invaluable.
I run a google group called Business Bootstrappers. I don't have a unified theory, but I did forward the links to this article, discussion and Startup School to it, which is part of why I asked this question. It has no goal of fostering what people call "lifestyle businesses" (a term I am not fond of http://micheleincalifornia.blogspot.com/2014/03/i-love-lucy-...), but it does have a goal of supporting businesses that aren't specifically looking to take VC funding.
"Lifestyle business" is derogatory propaganda by the investor class, who wants you to think like them and make more money for them. Every business is a lifestyle business, after all you only have one life. Investors want you to spend your time making money for them, instead of doing what you love. If you love making money too, then by all means listen to what they have to say, but take it all with a big bowlful of salt.
It's a shame there's not a Startup School-like resource for creating a lifestyle business (YC-like in that it'd have a unified theory of lifestyle business creation, as YC has for startups, that'd been honed through assisting in the creation of hundreds of such businesses).