with the seniority list in BA is that one guy will have a massively worse roster than another, simply because he or she is more junior. To old hands, that might seem reasonable, but not in the modern world of employment.
You're missing the point.
Without some kind of bidding system no-one will ever get anything they want
(time off or destinations) , whereas the company can roster as it likes to EASA limits.
It seems to me the modern world you refer to is zero hours contracts and no protection from ruthless employers.
I know which i'd rather have!