I just want the BA of old back please.
A broad brush I'll admit, but my ten penn'orth is that with the advent of cheaper fares, the airlines, including BA, had to ramp-up with more staff. The new (cheap) people had neither the service background, understanding or interest of the previous generation - just a job to them. BA (in the air and on the ground) were swamped with this influx of lower standards and gradually, to get the "old" BA", you had to fly "Club" and eventually "First" where some sort of service just about hangs on, albeit at eye-watering cost. Eventually, the crews/staff of the '80's and '90's just gave up the battle and we end up with the BA we see today.
That "old BA" style is still around however, - you can find it in some Indian and Asian airlines..