Airlines are in my experience among the least ethically run businesses:
* They will cancel a flight at the last minute stranding passengers because it was "undersold".
* They will delay flights for reasons that have no accountability to consumers.
* They pass on 100% of the risk of flights being on time to consumers.
* They give gate attendants authority to claim your bag is "too large" for the overhead bin even when it fits just fine. They can even claim the overhead bins are full when they are not full.
* Airlines will try to make every seat on a plane "economy-plus" (when you have already purchased a ticket, but they haven't given you a seat assignment yet) when they are overbooked and the bump the passengers that don't pay.
On the contrary I challenge airlines to find one example where they act ethically even when their incentives are not to and the law would allow them to act otherwise.