I’m not a fan…
I’m not a fan of Galbraith’s, but he and you are spot on about the mathematization of economics.
Penis envy towards the “hard” sciences is an important part of the explanation; I think the professional interests of planning bureaucrats (a common destination, or aspiration, for institutionalized economists) are another; a lot of economists have, after all, a professional interest in justifying their positions as number-compilers, number-crunchers, and number-fudgers to the powers that be.
Personally, I think the best critique of the tendency was actually published several years back, in the form of a parable, in a Calvin and Hobbes strip.
Anticopyright.