So this is how a mathematician can be a public intellectual:  Tim Gowers employed his characteristically lucid prose in the service of clarity in his cogent response in the Guardian to the Simon Jenkins column mentioned in my previous post.  I agree with everything in Gowers’s answer to Jenkins, though his examples that show how mathematics can “be a tool for increasing one’s thinking power” are drawn from statistical reasoning; making the case for the value of learning the area of a circle or the quadratic formula is more challenging, and I don’t know that anyone has found the right way to counter the complaints of those who share the Jenkins worldview.  (I suspect the solution must include the word “culture” but I’m not sure what other words need to be involved.)

A position on questions of education in mathematics or anything else rests implicitly on a theory of the good society.  Jenkins must have such a theory but I couldn’t figure out what it is.  Gowers makes his very clear:

…once you [understand some principles of statistics], you become better at making decisions. This is important for individuals – whether we like it or not, we all have to take major decisions based on statistical evidence – and it is even more important for people in positions of authority, whose decisions affect other people.

I would only add that, unfortunately, the politicians are not likely to be motivated to represent the interests of those who voted for them; and even if they are, there are structures in place that prevent them from doing anything about it.
However, it seems there is an alternative.