I think the “unreasonableness” we are seeing appear more in some passengers is a reaction to the unreasonableness of BA. How many times are we seeing that people just can’t get through on the phone lines or when they do they are given a poor response? People panic when far from home with few options to get them back in the short term. More so if they are infrequent fliers unaware of resources such as FT.
I agree that passengers should be more circumspect and follow some of the excellent advice here but that’s not human nature.