The whole topic is a hard one to call as I have been part of the system and like I say, having been BA crew for over 6 years I have first hand experience of what goes on. I hold my hands up and admit I got away with murder and going sick was as easy as anything with no questions asked!
I think crew are worried that the comfort of going sick when you don't want to go away or when you have your neighbour's 100th birthday champagne and caviar bash will have a real impact on their control over their working life at BA.
Crew used to have control over BA, but it is slowly turning the other way and it is not liked. From my humble experience crew did NOT go sick if they had a cold or even flu...the contrary, but up comes Ascot or Wimbledon and suddenly there's a rush of crew reporting "sick".
Believe me, on BA's flights to NRT, SIN/SYD and BKK/SYD sickness is practically non-existent as earaches and colds don't happen on these routes....funny that...$$$$$$$$$$
My guess is that things have got out of hand re sickness and that change is inevitable. Anyway, if you are genuinely ill, as long as you have a doctor's certificate there is little they can do...equally, if you are always ill, should you not get yourself checked out for your own peace of mind?