Id say it's anything but bad management. They've delivered consistent and robust profits and passenger numbers with record load factors. Airlines do not provide public services. They are profit making entities responsible for delivering return for investors.
They've adapted to changing markets and competition from the MEB3. People complain but they don't seem to have issues filling their flights and turning a profit.
No we don't have the national pride for BA quite like the Canadians or Australians do for their national carriers (despite being no better as a whole) but BA are still the airline of choice for many and for the others they will choose them if they're they cheapest. The amount of people who avoid BA just because they are BA is limited to a handful of people on here, airliners and flyer talk. Then you'll have the British haters who won't fly them because of their product but because of the stylised flag that they fly on their tail.