For those that complain about un-servicabilities in the cabin, come and have a look at most aircrafts Acceptable Deferred Defects (ADD's). I don't just mean BA I mean most airlines.
The problem comes not from 'over stretched engineers', though that is a problem for anything that can't be deferred, but time. An aircraft on the ground loses money. Plain and simple. Punitive slot time fines, airways fines and arrival delays cost a fortune. Hence, if the aircraft is on a short base turnaround and the fault is acceptable to the Captain then it goes.
Perhaps if we had to pay out less for the distress and discomfort of the crew at having an unservicable toilet or bunk lights then we could allocate more resources to making sure such minor fripparies like the passengers AVOD works correctly.
The company is there fore the shareholders, investors and passengers. Put them first.