This is why they didn't go back to the moon after the Apollo missions?

Apollo 17 (December 7–19, 1972) was the final mission of NASA's Apollo program and they never went to the moon again for some good reasons that time. 

Now after 50 years something has changed and with its Artemis program NASA prepares to return to and to land astronauts on the moon again as soon as 2025. As NASA states, they are going back to the moon for scientific discovery, economic benefits, and inspiration for a new generation of explorers and we may wonder what these discoveries could be, maybe the man-made structures and (alien)objects already reported by the Apollo crews but hidden from the public for over 50 years? 

Neil Armstrong said, look, you know, if I were to go forward and talk about what actually happened, it's been, I've been told Neil Armstrong said this to us, that my me, my wife, my children, and my grandchildren would all be killed. That they would take us out somehow. Some terrible accident. And he says, I'm not going to talk about it. 

Here is an extract from the original press release. NASA scientists and engineers participating in exploration of Mars and the Moon reported the results of their discoveries at a briefing at the Washington National Press Club on March 21st, 1996. It was announced for the first time that manmade structures and objects have been discovered on the moon. 

The scientists spoke rather cautiously and evasively about these objects, with the exception of a UFO. They always mentioned that manmade objects are possible and stated the information was still understudy and official results would be published later. 

It was mentioned at the briefing that the Soviet Union used to own some photo materials proving the presence of such activity on the moon, and although it wasn't identified what kind of activity it was thousands of photo and video materials from the Apollo. And also the Clementine Space Station showed many parts on the lunar surface where this activity and its traces were perfectly evident. 

The video films and photos made by us astronauts during the Apollo program were demonstrated at the briefing. People were extremely surprised why the materials hadn't been presented to the public earlier NASA specialists.