I have a bit of a different take. I would say pack the 10 essentials for all trips, unless, as others have said, you're going to a place where a knife or fire starter is prohibited.
The reasoning I use is it gets you in the habit of having these things handy. Most, if not all, can stay in your day pack.
I'm a counselor for the Hiking merit badge. I do expect the scouts to explain, beyond the 10 essentials, what is needed for a specific hike. If it's hot and water sources aren't plentiful, do you have enough water capacity? What clothing layers and footwear is appropriate? How mu