Black Rock and Area 51 are not comparable environments, Black Rock is much more forgiving for the unprepared traveller. I've gone off-roading in both regions extensively. Black Rock is a relatively temperate and populated area for Nevada, albeit rural, and Pershing County has decades of experience dealing with thousands of unprepared people. The region around Area 51 is essentially a bone-dry wasteland with a couple mining camps in the area and nothing else.

The carrying capacity for excess population around Area 51 is all but non-existent, and far smaller than in the region around Black Rock.