Now a recipe is a lot like a computer program.  A computer program's a lot
like a recipe: a series of steps to be carried out to get some result
that you want.  So it's just as natural to do those same things with
computer programs -- hand a copy to your friend.  Make changes in it
because the job it was written to do isn't exactly what you want.  It did
a great job for somebody else, but your job is a different job.  And
after you've changed it, that's likely to be useful for other people.
Maybe they have a job to do that's like the job you do.  So they ask, "Hey,
can I have a copy?"  Of course, if you're a nice person, you're going to
give a copy.  That's the way to be a decent person.

So imagine what it would be like if recipes were packaged inside black
boxes.   You couldn't see what ingredients they're using, let alone change
them, and imagine if you made a copy for a friend, they would call you
a pirate and try to put you in prison for years.  That world would create
tremendous outrage from all the people who are used to sharing recipes.
But that is exactly what the world of proprietary software is like.  A
world in which common decency towards other people is prohibited or
prevented.