You've missed the article's logic. I say the crucial factor is the humanistic culture of critical thinking and objectivity. That's what separates science from pseudoscicence. Economics is too politicized to be credited with having that culture. Astronomy and geology aren't.

Climate science is a more interesting example because global warming certainly has become politicized, and there may be an overreliance on mathematical models there too, as in economics. The difference would be in the greater consensus among climate scientists. Plus, climate science is built on nonpoliticized sciences.