It isn’t the only country, though. Japan does too. Basic facts…
What are you on about? I live in Japan. You can walk to the city office and get health insurance. Every resident is legally REQUIRED to have health insurance and many do not work. I got health insurance as a student when I first moved here.
He is right. In Japan there are 2 form of health insurance: from your company 社会保険 (shakai houken) or directly from the government 国民健康保険 (kokumin kenko houken). If you quit your job you loose your health insurance the very day you're unemployed and must go to your prefecture to ask the national one (you'll pay for it, around 200$-300$ a month).
Also in France your health insurance is also tied to your job. The french administration is a nightmare to me so I have no idea how to get anything if you're unemployed.
I took it to mean that there were no insurance options outside of employment, which isn't the case given 国民健康保険 exists. IIRC, a lot of people doing バイト and パート in addition to students and unemployed are on the same (or a dependent, which relies on their spouse/parent/etc.)
EDIT: Also, I think employers or a certain size (or maybe just 個人事業) don't have to provide health insurance, but I'm not 100% on everything around that off-hand.