Why discipleship without reproduction is not Biblical discipleship

You’ve probably heard this phrase said, in some variation:
“Discipleship without reproduction is not Biblical discipleship.”
Why? Because in Matthew 28, Jesus said: “Go and make disciples… teaching them to obey everything I have commanded you.”
The commands we are to obey include the command to make disciples.
Therefore, if a disciple is not making a disciple… he is not obeying everything.