Did you read the article, or do you just have strong opinions about health care? Either way is fine, but the point of the article is that one of the reasons twentysomethings are a huge fraction of startup founders is that they aren't locked into jobs by health insurance.
(It is also, by the way, simply not the case that twentysomethings are overwhelmingly the source of startup founders; what they do seem to be is an overwhelming source of YC company founders. Go make a list of 10 VCs, read their portfolios, and go look at the "Management Team" sections on their websites.)
Having re-read the piece, I don't see anywhere that he defines his point as being that "one of the reasons twentysomethings are a huge fraction of startup founders is that they aren't locked into jobs by health insurance." I'm sure from your personal experience you think this is the case, but the author doesn't assert that it's the case, or try to provide evidence that in countries with universal coverage there are more older entrepreneurs.
I personally think that health insurance is pretty far back on the list of reasons older people are less likely to found startups than young people. I'm willing to be convinced there by some sort of evidence. Regardless, in order for it to be the case that "[u]niversal health insurance, far from suppressing entrepreneurship, could be a boon to it," it would have encourage more older entrepreneurs than it discourages among the young.
Which brings us back to entrepreneurship. Some of tomorrow’s potential entrepreneurs are today’s employees at firms that provide health insurance. They may have powerful new ideas that will build the firms of tomorrow. But if they leave their current job to work on those ideas they may find themselves without access to reliable health insurance. If they are very young and healthy, this may not be a major impediment. But for older entrepreneurs who have developed ideas through years of working for others, the fear of losing health insurance when they go out on their own can be a barrier to taking that leap.
You're right, though. I used the word "the" when I should have used the word "a".
Anecdote != data, however, I will say that my decision to stay in my job is quite tied to the health insurance my family (w 1 child) receives through that job. It is simply too risky and expensive to take a lower paying job that might provide worse health insurance or part time work in order to attempt a startup.
(It is also, by the way, simply not the case that twentysomethings are overwhelmingly the source of startup founders; what they do seem to be is an overwhelming source of YC company founders. Go make a list of 10 VCs, read their portfolios, and go look at the "Management Team" sections on their websites.)