The example of the shipping industry is a relevant guide, the national carriers did not survive, but rather were replaced by the likes of a Maersk or a Carnival Cruises, specialized and ruthlessly efficient global players with only two or three surviving competitors.
If BA management shares that perception, they will be looking to reposition the enterprise accordingly, irrespective of the short term disruption.
That's a really interesting perspective. You might be right. If we take the example of cruises, with which I am becoming more familiar as the years advance, the old national lines taken over by Carnival still keep their national flavour eg food in the restaurants, ports of call, senior staff recruitment, language of signs etc. but are still part of one family. I was amazed to find that two totally different cruise experiences (good but that's not the point) from Cunard and Holland America Lines respectively were in essence both run by Carnival who use their massive dominance of the industry to generate economies of scale. There are advantages in having different brands for the same product supplied by a monopoly supplier. If that is the case, then pax suggesting they will never fly BA again because of poor service are wasting their time because what they really need to say is that they will never fly IAG again, which will be difficult.