The whole thing is predatory pricing sold under the illusion of "choice".
The original hold baggage charges were brought in and the airlines thought most people would pay it. They didn't. So in response the cabin baggage sizing changed. Ryanair, for a while, had a maximum cabin bag size that was about 2cm smaller than the common cabin bag size; clearly this was designed just to trip people up.
Even that didn't work, so now the airlines make you pay for anything bigger than a small rucksack. EasyJet are the worst for it- they are extremely aggressive about it at the gate. And it's clearly an edict from the airline, as the gate staff at Isle of Man who are so aggressive on the cabin bag sizer are the same ones who are lovely when they're despatching the Loganair flights.
I try to fly Loganair as, with them, what you pay is what you pay. And they're usually pretty good if you inadvertently go slightly over the hold weight. And once you've added a £30 hold bag to the £30 fare then the £65 Loganair fare doesn't seem so bad after all.
As for the original justification of 'hold baggage being more expensive to process', hmm. Two things are very telling:
- on all my recent EasyJet flights it has been cheaper to purchase a 15kg hold bag than it has been to purchase a cabin bag; and
- Aer Lingus give you a 'free' cabin-sized bag but make you check it into the hold; you have to pay extra to take it onboard with you.
Goes to show it was never about cost and it was never about consumer choice. It was all about predatory drip-pricing.