The defense comes from Billy Wilder's Sabrina (the 1954 version) with Humphrey Bogart playing the ever serious Linus lecturing his playboy brother David on his motivation to come into work everyday and make the company ever more successful. A tad glossy, but a succinct argument on why capitalism is a force for good.
David: You've got all the money
in the world.
Linus: Making money isn't the main point
of business. Money is a by-product.
David: What's the main objective? Power? Ah! That's become a dirty word.
David: What's the urge? You're going into
plastics. What will that prove?
Linus: Prove? Nothing much.
A new product has been found,
something of use to the world.
A new industry moves into
an undeveloped area.
Factories go up, machines go in
and you're in business.
It's coincidental that people who've
never seen a dime now have a dollar
and barefooted kids wear shoes
and have their faces washed.
What's wrong with an urge
that gives people libraries,
hospitals, baseball diamonds
and movies on a Saturday night?