I would say that school does help. It exposes people to different ideas and topics (Wait, I can get paid to do something with math besides run a business? You mean I can spend my entire life researching something?).
Personally, my opinion is that its absolutely great to know a lot about your specific field that you (want to) work in. But I would never want to limit myself to only knowing about one particular topic of knowledge.
//edit (to reply to this bit): If people started working at 14, or even 18, people would have a lot more time to discover the career they loved, before they had to assume the burden of earning enough to support a family
There's a lot of careers that require years of training to go through before you can begin working. Lawyers, Doctors, etc. We on HN might like to think that anyone can pick up a profession and just hack away and be able to make a living at it on whim. But it doesn't work like that. Its not as simple as deciding "I don't like being a lawyer, but I think I'd like being a farmer. I'm going to buy some land, plant seeds and call it a day".
I'm three years out of college. Most of my friends had no idea what they wanted to do in graduation. They picked a job, didn't like it, and now are switching. Except now the biological clocks are ticking, and it's becoming more important to pick the right path, because there is a major costs in switching careers.
If people started working at 14, or even 18, people would have a lot more time to discover the career they loved, before they had to assume the burden of earning enough to support a family.