Same reason you don't go to a trash club with a price that would make you broke, 8 times if you have other options

China are sending unmanned ships to the moon now, cause they wanna show that they are a "super power" too.
Not only was there photos of their boots, rocks brought back and photos from earth from that can identify what they left up there. Why the hell would our worst enemy that we were in a 40 year long war with confirm it?

How could nearly 4-500k who worked on that shyt hold their silence regarding such a soft joke for half a century when do whatever for 15 minutes of fame?