Any argument made by starting with calling someone rude or accusing them of having a superiority complex, can only be made better by instead empathizing with rather than dismissing opposing viewpoints.
What's even worse is patronizing a mis-characterization of someone's statement.
> I roughly divide human activities into jobs and hobbies.
This indeed is a rough characterization of life. At no point does shaftoe insinuate humanities and arts are 'hobby educations'. Rather it seems to me a simply capitalistic view that anything humans do well can be done for money, at which point we call it a job. Certainly that also includes artists and philosophers. Or another way to think about it, to be truly great at something you must spend the majority of your life doing it, at which point it probably also needs to pay the bills.
People should only be investing 5-figure sums of taxpayer's dollars to learn what they expect will be lifelong skills that will significantly increase their lifetime earning potential. In almost all cases, this is not Art History class.