You missed part of the idea: "if you accept to work for free".

The parent was saying (if I understood correctly): "stop complaining, you should accept the business decision, because that's what a company does: optimize the profit without caring about how the employees feel".

I was just saying that as an employee, you have the right to negotiate your working conditions. If you accept all the "business decisions" because they help the company make more profit, then they will stop paying you. That would be completely rational as a business decision.

If I accepted to work for free, I would be absolutely fine with the company taking me up on the offer. I'd be shocked if they didn't.