I don't think the passengers are ignorant, I think they don't pay attention, like the ones ridding on every other carrier and can't follow tsa, gate agents and crew instructions.
The website where they purchase the ticket explains the bag charges also
every single ticket counter has a sign explaining the bag charges, specially the one AT THE GATE being $100. I commute on AA and passengers can't seem to understand that they have to move away from the gate to let the deplaning passengers out, or to turn off their electronics, more than 3 times,
Everyone is too busy on their phones to actually pay attention.