...but even with voluntary moving, the hassle of moving passengers, potentially moving baggage, and also lost customer loyyalty, is not a great situation. Not to mention the compensations, monetary and otherwise (e.g. booking a night in a hotel if necessary, vouchers etc.)

AGAIN: there are already measures in place to punish reckless overbooking, but the practice *on the whole* isn't going to go away if we keep working under the logic of maximising profit.