Everyone has different views on what Liberal vs. Conservative means, but if you were to use these definitions:

Liberal: Promote group-oriented solutions to address economic disparities and historical social injustices.

Conservatives: Promote individualist-oriented solutions to create wealth and entrepreneurship.

... you'd start to see that the author's argument is a little circular.

'Education', in the author's sense of the word, refers to group-oriented institutional education (e.g. traditional universities).

So really what the author is asking is 'why do people educated in group-oriented educational institutions promote group-oriented political solutions?'

I think it would be interesting to know where 'self-taught learned people' sit on the political spectrum?