My guess is those vacations were booked long before checking the weather. Sure maybe a sunk cost thing but the commitment and scarcity of time off is pretty understandable
Maybe for some tourists it's the extreme heat and dryness that defines what's unique about the desert experience? Beats me.
Even that well-known search & rescue story of the "Death Valley Germans" dated their van rental from July [0]:
> The vehicle, owned by Dollar Rent a Car, had been rented to a group of four German tourists in Los Angeles on July 8, 1996.
> The vehicle had been due back to the rental agency in Los Angeles on July 26, but had never been returned.
