I think the little prince is being a contrary little shit. I'm sure sometimes he would prefer to play in the park, jump-rope with friends, or draw a picture than just walk an hour whether he wanted to or not.
I do agree with your view of the Little Prince. Still, the irony is, the validity of the merchant's argument is irrelevant. 53 person-minutes per week is a tiny benefit compared to eliminating logistics around manufacturing and shipping beverages.
For better or worse, in real world, conditions like these end up with the market forcing adoption of the solution, whether the people on the receiving end like it or not.
"Why are you selling those?" asked the little prince.
"Because they save a tremendous amount of time," said the merchant. "Computations have been made by experts. With these pills, you save fifty-three minutes in every week."
"And what do I do with those fifty-three minutes?"
"Anything you like..."
"As for me," said the little prince to himself, "if I had fifty-three minutes to spend as I liked, I should walk at my leisure toward a spring of fresh water.”
― Antoine de Saint-Exupéry, The Little Prince