The reason GA wages are so poor is because of flying schools which churn out commercial licence holders like a sausage factory. As a result there is a massive oversupply of low hour commercial pilots and the wages reflect that.
If these schools were more honest with prospective commercial students, they would have a huge downturn in CPL training, so as a result they will say anything to get people to part with their money.
A simple case of supply exceeding demand.
I believe all new commercial students should have to read and sign a declaration upon enrollment which states they are aware of the wages and poor employment prospects on completion.