"If there is absolutely no way you can imagine being happy except studying philosophy, study philosophy. Otherwise do something else."
I'd say the same thing about starting companies.
Sounds good, but... wait a minute.
Most people have no ideas what it means to start a company, what it consists of, what it feels like, etc. Chris himself admits so much in the intro to this brief article. I certainly didn't have the foggiest idea what running a company is like when I quit my "safe" consulting job. I had to learn on the job, and it took years.
Today, I wouldn't want to do anything else. But this realisation took some time.
So, perhaps Chris's point should be paraphrased somewhat, to:
Try running your company. Try it for a few years, until you're ok at it. If you still can't imagine anything better, keep at it. Otherwise, do something else.