Pay isn't the issue, rural areas have low cost of living in general and the pay is actually pretty good. Not SF tech wages good, but still good considering not much education is required for the labor jobs. (the farmers make a ton of money but that requires good management because the one great year makes up for many years of losses)

The real problem is that it is a job where you are along for hours every day, in a rural area where there aren't many options at the end of the day for fun. Cities have some nice points, most people would like farming for a week and then get bored.