Some facts to consider:

• This happened in New South Wales, in a very rural area. People are not going to commute out to this remote location for minimum wage.
• Kids volunteer on the weekends and parents sign off on it.
• Some of the kids like it because they don't have anything else to do, they learn a job skill, and they make a little money.

That said, I don't agree with it. Hire adults and do what everyone else does by having a "bring your child to work day/week" if you want to teach kids. Or make a field trip. Let's not go backwards in society to benefit companies.