Farmers got used to scamming backpackers for WHV extensions now suddenly its wont someone think of the farmers.
Not all farmers, just some, like other parts of the community there are some that take advantage of everything cheap thinking it's best. I know a few other fruit growers that pay top dollar during picking season to ensure fruit is harvested quickly and in good condition, and they employ repeat pickers that come every season as they are reliable, some from the city. It's not easy work, but rewarding financially for those that do the job well and work for the right employer. The other option is to not care about quality and just employ cheap as possible, which is usually a sign of poor business acumen.
Harvest is no different, you want the right people operating millions of dollars of machinery in combination with millions of dollars of crops. Harvest at the wrong time, wrong moisture etc etc etc, you could lose tons of yield. Hit rocks, posts etc in afield with a combine, not only the damage bill, but the loss of work/harvest while the vehicle is repaired.