There is still so much to find on the Moon!
Women never have been to the Moon. Can we stay longer (with 14 days of continuous sunlight), can we have humans on the Moon for a Moon night lasting 14 consecutive "days", with no solar energy to count on?
Can spacesuits last months and be used on a dayly basis with such temperature differences and so much dust?
How about visiting Copernicus, Aristarchus, the Schröter Valley, Rupes Recta, the poles...with a wheeled pressurized vehicle? While moving, the vehicle will be bouncing all the time, and will do as well on Mars! Be careful for the stomachs!
Can humans explore Farside without any contact with Earth for days, can they also do it during the Moon's night?

All those scientific and technical aspects of explorations are not mastered yet and the Moon is right there, not too far but far enough.

I saw Zubrin in 2001 in Holland and exactly one year later, Schmitt, at the very same place.

Several differences. Zubrin had a much younger and larger audience than Schmitt. But Zubrin wasn't always surrounded, in fact he went to sit alone on a seat at the auditorium while others were making speeches before his turn. When he first arrived, it was very easy to talk to him as few were around him anyway. Schmitt was always surrounded and close to others at all time and it wasn't easy to be able to privately talk to him. Schmitt's experience was met with far more respect (and deference) than Zubrin's.

And I'm not very enthralled by someone who's got to destroy our wishes to return back to our nearest neighbour before we can visit the red planet.

It's always easy to defend a very ambitious program in its infancy when few realize all the details that need to be assessed when the safety of the astronauts is at stake.

NASA, in 1972, came up with a Shuttle which wasn't meant to have escape means once 4 test flights had been accomplished and once a certain speed and height were crossed. Thinking about all the escape means wasn't in their minds so long before the first flight.
For the Moon, we have some ideas and experiences from the past, on those matters, and we also have the proximity to our planet. We have the same Sun energy as in LEO.
Thanks to the proximity, flights are shorter, which means they can be more frequent and involve more astronauts. Rescue flights can reach the Moon on shorter notice and don't need a 26 months launch window.

Truly, the enormous distances involved with Mars make it so much more complicated! Fewer astronauts involved, with much longer and fewer trips (where nothing exciting happens for months) and far less missions (and much more time passing) to test the feasability of such a flight.

While we've only visited a few square kilometers of the Moon, so far.
So much remains to be done on the Moon.

Raoul