Have you ever considered a perfectly logical explanation for not seeing any stars in photos. Stars are actually difiult to photograph. They appear relativeley very small and are not very bright ( try reading a news paper by starlight). They require very long exposure that can be measured in hours not minutes. You may well have seen those photo where stars appear as fine tracks of light. Effect caused by the rotation of the earth over the long time required to get the photo. This affect is counteracted by motorized tracking devices on telescopes.no stars etc
In contrast photographs of astronauts would require quite short exposure. First this is necessary if the astronauts are moving but secondly the light levels on the moon can be higher than on earth as there is no atmosphere to reflect and absorb the radiation.
I would assume that camera used on the moon where quite simple because various technologies were not available then and because of the difficulty of operation in a space suit.
The cameras where probably fixed focus but anyway would be focused on objects in the fore ground ie astronauts rocks etc. meaning objects in the background ie stars would be blured.
Add this bluring effect to the fast shutter required because of the light levels then it is not surprising that the little light from stars does not register on the film.
Hense the stars where there they were just not caught on camera
) was one of the original Mercury 7 astronauts (buy the DVD, "The Right Stuff") )