Because of the atmosphere diffuses all the blue from the sunlight all over the place. I've seen people demonstrate that if you know where to point a telescope, it is just about possible to make out some of the brighter objects — though I can't remember if that was a star or a planet…
But in this case, the exposure is set at a level that even Venus isn't quite fully saturating the sensor.
On the moon, the sunlight bouncing around is still enough to outshine the stars
Yup, it's less to do with atmosphere and more with exposure.
Shots of stars at night have exposures of a few seconds to get them to appear. Shots in the daytime are more like 1/60 sec.