abc - agree with much of that, but we are treading over old ground here on this accident. There is no attempt solely 'to blame the manufacturer'. You will see that the accident was primarily caused by poor flight and cabin crew performance. HOWEVER, as with all accidents, the other factors are contributory.
Many airlines had inadequate training on the horn activation pre-Helios - BA had several instances of 'confusion' in the simulator lasting varying amounts of time for reasons well-covered in the old thread. Only post-Helios was the manufacturer's information, QRH actions and training emphasis updated. Cabin crew were made more aware of the ramifications of mask drop, door procedures were looked at, engineering procedures amended. Only post-Helios did we discover that a particular failure mode CAN allow the TOCW to sound when airborne (via PPRune?).
We have (hopefully) learnt a lot from this accident.