The bag fees came about because the tax increase on the price of airline tickets. This was a way for the airlines to move some of the ticket price out from the tax. Drop the tax and then the airlines will drop the fee. Donald Trump will sort this out.
If the fee results in more net income for the airline, why would they drop the fee after an airline tax gets released? I think they will drop the bag fee only if and when they become convinced that dropping the bag fee will enhance the airline's net income. They aren't charities.