This just happened to me the other night.
I’m in a dispersed camping spot in a National Forest. It’s not crowded. I go to sleep around 9:30PM and wake up at 4:30AM to someone parked right next to me. There’s no trees between us and no possible way that they did not see my car.
As I drive out of the forest I pass dozens of empty spots.
This has happened to me twice. Who are the people who do this? There’s no rational explanation for it.
I may have an explanation for you. There are two state parks near me that require people to park next to each other. You can actually get towed for parking off on your own. They say they’re trying to get as many cars in the parking lot as possible.
Maybe that person is used to these sorts of rules.