When someone suggests it's outrageous an unskilled intern who will need to be trained on the job from the ground up will not be paid just ask them how much profit they estimate that intern will generate.

That kind of thinking both suggests the time of the person doing the training is worth nothing and also counter-signals to onlookers that the individual complaining doesn't understand even basic market concepts.

If you work there unpaid for 3-6 months and nobody else wants to pay you to leave then your market value is zero. If someone does want to pay you then you can just leave. Problem solved.

That topic is such a massive unintentional self-own for the people who think they are on the moral high ground for making vague uninformed blanket statements like "everyone should be paid for their work".

I don't expect a generation that wants to go to university to party and major in basket weaving but then expects everyone else to pay for it from taxation to understand the central point, though.