Is this viewpoint specifically because of lack of context as how far away help can be?
Though thinking about it, I think you average American city dweller probably would have a same mentality
We were told to bring water, but I only took a small water bottle, and it didn't last that long. I was kind of shocked when my vision just went all blank and red with some random sparkles. One moment I could see, the next I was fully conscious but blinded. I wasn't that far away from other people, but I wasn't right next to anyone. Luckily I wasn't that far from rocks that provided shadow where I could get out of the sun, but I was afraid that by doing so, I would be hiding from anyone who could find me. And briefly I had no idea if my condition was permanent, I was going to die, or what.
Anyway, I wasn't a European or city dweller, just a clueless kid not used to the desert and/or outdoor activities much.
I think a lot of people do dumb things, and some survive and learn, and some don't.
When I hear people gushing about colonizing Mars, I think about how deadly parts of our own planet are. I just shake my head. Probably 99.9% of our population is completely unprepared for that level of hardship. I know I'm not.
Even when you do the terrain isn't anywhere near as inhospitable as the American desert.
That being said, even 1 mile is enough.
At least in there places, you're never far from a water source. Maybe carrying water is a bit difficult concept for Northern Europeans, as you can always find drinkable water in the nature.
Edit: spelling
It also depends on what kind of nature you have around you. In my case, mountains. Others have deserts, forests, jungles, arctic... Some principles transfer well, others not so much.