How we cite our quotes: (Act.Paragraph)
Quote #4
Because people would stone him to death. After all, it's more convenient to let Robots do your work for you. (1.301)
Gall says that people would attack Domin if he got rid of the robots. People like having a working class—or at least, people who aren't working class like it.
Quote #5
In Le Havre the first union of Robots has been instituted—and has sent out an invitation to the Robots of the world…
So you see, Helena. This means a revolution, understand? A revolution of all the Robots in the world. (1.378)
The Communist Revolution is imagined as a Robot Revolution. Marx, the founder of Communism, thought the worker's revolt would be worldwide, but really there were only Communist revolutions in one or two places, like Russia and China. The robots do better though. They're not just better workers than humans, they're better rebels.
Quote #6
This is nonsense. They go on to assert that they are higher than man on the evolutionary scale. That they are stronger and more intelligent. That man lives off them like a parasite. This is simply heinous. (1.471)
Robots may or may not be higher on the evolutionary scale, but humans in the play do live off them like parasites. Maybe Domin thinks it's heinous because it's true?