Again, this is about different ways of learning which ties into what is even the purpose of programming in the first place.
For academics, the purpose of a program is to exhibit some clever abstraction. So a quicksort which can't take any input to sort and can't produce any output is a perfectly fine program - almost the platonic ideal of a program.
But for developers, the purpose of programs is to do something useful. So learning how to read input and produce output is basically the first thing I want to learn when learning a new language or platform. Because then I can start building small toy programs, gradually doing more and more stuff and learning by tackling the challenges along the way. And implementing quicksort comes way down the line of things I need to learn to write a useful application.
For academics, the purpose of a program is to exhibit some clever abstraction. So a quicksort which can't take any input to sort and can't produce any output is a perfectly fine program - almost the platonic ideal of a program.
But for developers, the purpose of programs is to do something useful. So learning how to read input and produce output is basically the first thing I want to learn when learning a new language or platform. Because then I can start building small toy programs, gradually doing more and more stuff and learning by tackling the challenges along the way. And implementing quicksort comes way down the line of things I need to learn to write a useful application.