Including a tarp in your day-pack makes sense anywhere you might have damp or cold-damp weather and you can string up a tarp and have a fire - for comfort or in an emergency.
The activity we RVers refer to as boondocking is made pleasurable by a combination of learned skills, adjusted or changed habits, a desire to stay out in the wilderness as long as comfortably possible, and a curiosity about out-of-the-way places, nature,