A mission to the moon wouldn't be as inspiring as going to Mars. Twelve humans have already landed on the moon and returned. With advanced robotics, NASA and the European Space Agency can send probes to the moon instead of humans. A manned mission to Mars will be exciting, but private companies should foot the bill for it as opposed to taxpayers. We need to solve Earth's problems first before stretching our reach to another planet in our solar system.
A mission to put people on the surface of the Moon has already been done. The samples of rocks and dust collected there showed no real promise for any economic use. Mars is farther and much more "alien" in the minds of the people. Mars may still hold resources that we could economically find use for.