There is a lot of fixating on the lowest pay point which I don't really understand.
In my opinion looking solely from a monetary point of view, attaining a quick command and potential LTC position in Easyjet etc is going to be lucrative in the short term. My own quick ballpark maths, which may be incorrect, gives me an age of 31 as the point where it is not worth joining BA, from a monetary point of view.
If I were lucky enough to join BA I would certainly lose a considerable amount of cash over the next 10 years, but I should in time catch up. There are plenty of young pilots that don't want to endure the pain for the longer term gain because they do not wish to sacrifice their current cash-flow and lifestyle, a perfectly valid outlook. Each to their own. For me, the decision to apply to BA rests with lifestyle and longterm gain.
Comparing apples with apples I believe KLM and Aer Lingus offer a similar starting salary to BA? I have friends who joined SAS recently who describe living on their pay point one as "challenging". The decision to join these career airlines is not about starting salary, for me at least.