While I don't share the pessimism or sense of superiority one might read into OP's post, I think their point remains (somewhat) valid.

There are many people who 'endeavor' exactly the way he describes, many more than I always wanted to believe. And many of them are quite intelligent, so it's not just about IQ.

While changing our approaches to education and the right motivation, in my opinion, can bring people much further than some of us are inclined to believe, this is a limited solution for all the grownups who live in the way OP describes.