Why not? If someone has a degree in something technical I could imagine following a curriculum consisting partly of corporate finance management, fundraising, HR and other corporate issues for a year could be valuable, especially if they offer night classes or something like that so that you can still be working on your main idea.
Most college new grads are not exactly CEO material from the get-go.
I would assert that a recent graduate who wants to be an entrepreneur is mostly doing themselves a disservice by studying those things. It focuses your thoughts on how to run a business rather than how to solve a problem or turn an industry on its head.
Sure, many of those things could come in handy in the future - but there are far more difficult things which you also have to learn "as you go".
Interestingly, I see several tech startups of this nature started by folks having a deep understanding of a specific business problem due to their prior work experience tend to create such startups.
As a service provider for small businesses, I see many amazing bootstrapped services & products come up around the world, that serves a very specific need for a small subset of customers. These viable businesses tend to make enough for the needs of 2-3 folks for a long time. I have a strong inclination towards finding many of them as a service provider because they just tend to be some of the best customers with great ROI.
I am indeed concentrating on the types of companies YC would invest in. I don't know anything about lifestyle businesses but what you say sounds reasonable.
You're going to be better-equipped to solve a problem or turn an industry on its head if you are not also discovering how to run a business at the same time.