There are obvious ways that the physics engine might be able to capture more effects than a simple analytic solution of parabolic trajectories. But if it only lets you run the simulation forward to get a trajectory from initial conditions, then you now have a numeric optimization problem as the body of the inner loop of another optimization problem.
If the physics engine can't efficiently solve the inverse problem here, it is probably only well-suited for simulating a final solution for validation, not iterating over the rather large space of possible shot trajectories times possible backboard angles at the point of impact.
