Aldrin: I can tell you the Moon is a dead end for NASA.

What to do?

Drop humans in low earth orbit?
Don't send humans back to the Moon?

Then what happens?
No humans in space at all for 30 years and all of a sudden, a manned flight to Mars?
Where will the expertise come from, how can humans be trained for such a long flight ?
In order to go to the Moon, after Shepard's ballistic flight, NASA needed to orbit astronauts (Mercury), manoeuvre, rendez-vous, dock with another spacecraft, spend enough time in weightlessness for a trip to and back from the Moon, spacewalk (Gemini)....and train astronauts for the Moon (Apollo 10 and 11 crews had all been in space before).

No humans in space for 3 decades in order to save money for Mars, will that be politically defensible? (far less jobs for space as there's less activity and far less publicity and encitment to go up there, far less space related science tought as there are no ambassadors up there).

And the Moon is no place to train for Mars? Every single world is different from the other (well, especially worlds withj an atmopshere, airless worlds differ only by their gravitation).
The Moon is far closer, visible, a world to study and test equipments. The Moon has properties like constant shadow or constant sunlight ,a farside and a nearside.