Originally Posted by
BenA
Safety; the regulators wanted there to be no financial incentive to pack people onboard a 50 seater regional jet busting safe weight and balance numbers. The smaller aircraft are subject more to the whims of weather, making it more difficult to plan for the 100% case. In contrast, mainline aircraft are usually only subject to weight and balance issues as a result of - as you say - poor planning (like flying a classic A321 to Hawaii or out of SLC in the heat of the summer).
In the new world where airlines try to never IDB passengers, it's more or less a moot point anyway; now that the UA incident has incentivized the airlines to only use volunteers at any cost, the financial incentive is back to bust safety margins in favor of volunteering out fewer people.
I could understand that for a scenario that happens once in a blue moon. But if a pattern emerges then the airline needs to face severe consequences. Bait and switch is illegal. When you sell a passenger a ticket for a flight on a certain day at a certain time then the airline should be making a good faith effort to honor their end of the agreement. It would be better to make the airline make a scheduled fuel stop than to have the freedom to kick passengers off without compensation.