I always find it interesting that when you open a quantum mechanics textbook you see pages upon pages of math. When you open an economics textbook, you see lots of words and very few equations (at least compared to the other sciences). If anything, the complexity of something like economics should merit more math than QM, not less.
Hint: There's often lots of math, little of substance, and its proof that lots of math by itself doesn't mean anything...kind of the like the OP incidentally...
/and I am very sympathetic to the idea that economics is not a science.
Yes, all but for the fact that there is less meaningful mathematics in economics than in most sciences and pseudosciences. It's one thing to describe some aspect of economic behavior with words, but quite another to try to meaningfully quantify that description with an equation.