When I asked Noam Chomsky to provide an example of a great polymath from history, he gave the example of his uncle from the 1930s who he said never went passed fourth grade! "He was one of the most widely educated people I've ever seen", he said.
You're right, the current education system in general (there are exceptions, of course) delivers the opposite of what it should. Education has become a tedious, meaningless, often painful exercise which suppresses human potential rather than unlocking it.
We must revert to the basic questions about education: what is its purpose supposed to be? Who benefits and how? What are the most effective tools and methods to achieve this? Ken Robinson has a lot to say about this (I also interviewed him for the book).
Autodidactic (self) learning is often an approach polymaths have taken over history (out of choice or necessity). So either we revolutionise the education system or, as Ralph Waldo Emerson suggested, simply 'Trust thyself"...