More importantly, writing is an important mode of communication in a way programming will never be (and programming shouldn't be expected to be that).
Penpals don't mail source code back and forth to each other.
Thinking knowing to code is as important as literacy is just another version of people thinking their specific profession is super-important because it's what they spend their time doing. I imagine some especially pompous auto mechanics think knowing the internals of a car is as important as reading and writing. (Though, I imagine there are much fewer pompous auto mechanics than pompous hackers.)
Penpals don't mail source code back and forth to each other.
Thinking knowing to code is as important as literacy is just another version of people thinking their specific profession is super-important because it's what they spend their time doing. I imagine some especially pompous auto mechanics think knowing the internals of a car is as important as reading and writing. (Though, I imagine there are much fewer pompous auto mechanics than pompous hackers.)