We know that airlines overbook their seats, then count on no-shows and rebookings to make the system work. This helps ensure that each flight will be as full as possible, but it also leads to situations where passengers must be paid to take a different flight. What if the airlines are doing the same thing with overhead bins and “allowing” more carry-on luggage than a plane can even hold? What if they’re overbooking those compartments in the hopes or expectation that some passengers won’t bother with a Rollaboard and will simply check their bags instead?
If that’s the case, then the aisle pandemonium can’t be chalked up to passengers’ misbehavior or to honest confusion at the gate. No, it would mean that all this hassle is a natural outcome of the airlines’ cabin-stowage arbitrage. It would indicate inconvenience by design.
It's a combination, but mostly the risk of loss and inconvenience outweighs the cost for most passengers.
I mean I remember before they started charging for checked luggage and after, and after they started charging the occurrence of "the overhead is full" on my flights went from rarely to every single flight.
I've switched to a carry-on that can fit under the seat in front of me to avoid ever having to check my bag.
If they switched which item was paid (i.e. first piece of checked luggage is free, carry-ons needed to be paid for), bet that the overhead bins would be a lot emptier.