I think a lot of the cabin crew are/were looking for the 'glamorous life'. Seeing the world, having fun in far away cities and maybe even sex and rock&roll. That may have been the case 20 years ago. Nowadays it is almost like a real hospitality job where you work long hours (albeit not 5 days a week, like most hospitality professionals) and pay is significantly reduced (albeit not for the 'old hands' at BA or for most at BA for that matter).
The result is frustration and anger. This is also a good explanation for the ease with which BASSA succeeds in creating such dichotomy. However, since the cabin crew are client facing the first person who suffers is that client. It will take a humongous effort by BA management to reverse this change in culture. Something the likes of Virgin don't have to deal with, since they are very new to the game.