[racket-dev] Why is the Systems Programming guide using console-oriented Racket?

Is there a pedagogic reason why the Systems Programming guide
explicitly discourages running through DrRacket?

There's a leading paragraph in the intro:

    To get into the spirit of this tutorial, we suggest that you set
DrRacket aside for a moment, and switch to raw racket in a terminal.

But frankly, I don't get this.