The goal is to prove that under certain conditions it is justified to take from Able Abel and give to Hapless Harry, and for the other eight people to engage in the use of force in order to do so. In fact, there are some who already agree that use of force against Able Abel is justified.
There is one major problem with the scenario. It conflates a political obligation to help Hapless Harry with a moral obligation to do so, and that conflation is exactly the trap that Progressives hope people will fall in to. If Abel Able helps because it is the right thing to do, he is not a slave unless one is to call him a slave to his conscience. But according to progressives, unless Able Abel is forced to help then he will refuse to help. That hidden premise, that Able Abel would not help unless forced to, is actually quite monstrous, and says far more about progressives than libertarians.
Of course, the progressive response would be to say that libertarians are of course selfish. This is asserted without support, as if it is somehow self-evident that a desire to not steal from others is selfish.
Contrast this to the way the heroes of Ayn Rand’s novels behaved. The Classically Liberal Student described the scene from Atlas Shrugged where Dagny Taggart saw a beggar on a train.
Dagny actually looks at both men and sees that neither views the other properly: "The two men were not human beings to each other any longer." The tramp gets up, ready to jump, grabbing the small bundle of his belongings. Dagny yells out: "Wait." Rand wrote, "'Let him be my guest,' she said to the conductor, and held her door open for the tramp, ordering, 'Come in.'"
She offers the man a seat and asks him when he last ate. He responds, it might have been the day before. "She rang for the porter and ordered dinner for two, to be brought to her car from the diner." Damn, Rand, she missed a chance to prove that her critics aren't liars!
The tramp and Dagny talk. He tells her he doesn't want her to get in trouble. She wonders why she would, and he says because she must be traveling with a tycoon to be in her own car. She says she isn't. He assumes she must a tycoon's wife then. She says she isn't. He responds with a knowing, "Oh," implying her purpose was that of a prostitute or mistress. Was this where she sends him flying to his demise? Damn, not again! Instead, she laughed and told him she ran the railroad. They share dinner and conversation for several more pages. What a monster!
He goes on to describe how Ayn Rand herself reflected the generosity of the characters that are heroes in her novels. And yet it is still asserted that libertarians are greedy, objectivists are greedy, that those who advocate liberty and the free market would never help Hapless Harry without being forced to do so.