For the same reason we study theology, they are both self-fulfilling prophecies. Humanity is known to have an excessive interest, faith, and hope in manmade make-believe, expecting it to deliver answers we so desperately crave.
The study of economics is steeped in a confounding of consequence and cause yielding grave depravity of reason lacking dependable predictive value simply because years of suboptimization of undesirable consequence is unlikely to revert to an identifiable cause. Entropy is a one-way street, from cause to consequence only.
So, we study a voodoo science of economics, complete with invisible hands and endless elasticity to prove we can make any economic theory fit the outcome.
In all seriousness, we must reinvent economics for it to begin to deploy the thesis that determines what can be discovered (Einstein). Not with stale absolutism of its belief system but with dynamic relativity in sync with the resources, humans, to which it is applied.