As an interested outsider and user (SLF), I have followed this thread with interest. I am employed in aviation, but not in the airline industry.
I have used LHR and BA (nee BOAC) from the late fifties up to 2005 and LGW from 1990 until the same time. Generally, the experience was a positive one and frequently came across front line staff that were professional and courteous. At the end, especially at LGW, luggage was slow to arrive at the baggage hall.
Lately, I have avoided LHR and LGW, only using regional airports and debacles like this only reinforce my reasons for doing so.
As a customer, an airline HAS to achieve two things before I will consider using it, firstly, safety (obviously) and secondly, a demonstrated ability to get myself and luggage to my destination together. Price, timings, comfort, service etc are considerations which come later.
Whilst I have on occasions travelled with only hand luggage, this has been my choice and not the airlines. When taking luggage to check in, it is completely unacceptable to arrive at the airport and find that the airline will not accept checked in luggage and expect me to travel without it.
An airline that expects me to check in and travel without my luggage will NEVER get my business again. BA appears to think that it is acceptable for an airline to offer travel on this basis.
It remains to be seen whether my view is in the majority, but I think that BA has crossed the line and is now in terminal decline, unfortunately for the majority of its workforce.