Mundy,
It has to come down to your personal decision at the end of the day, if you truely feel what you are saying then don't bother. The simple fact of the matter is that B.A. can afford to have this long indepth process because of the number of applicants. The ratio of successful candidates may be low but B.A. obviously feel that they are only interested in getting the best pilots/people possible. Whether you agree with the process is really of not much importance, if you want to work for them then you will go through the process. If the thought of working weekends puts you off then don't apply!!
If the situation ever arises that B.A. don't have enough applications to fill the positions (highly unlikely) then they will have to look at the standards they have set and may reduce the requirements to pass the selection process. In the mean time put yourself forward and see how you go.