In days gone by in HM Flying Club, if a WRAF got pregnant she was promptly shown the exit and that was that, no return to the Service, game over. If it was discovered that somebody was a homosexual they were out on their ear without question. Both situations have changed vastly since HMG have had to toe the line in the same way that civvy businesses have had to for far longer. It's the law, so there. Similarly, you didn't get a Married Quarter unless you were married (I recall having to show my marriage certificate to the Families Officer before the paperwork to secure a quarter was even taken out of the drawer). These days they're called Families Accomodation and marriage is not necessarily a factor in getting into one. Times change and we move with them (eventually.....sometimes).
I think that that is at the crux of the discussion. If we have to move on to satisfy the modern world and its associated legislation (in all its forms) then surely employment contracts within HM forces should also be changed to reflect the 21st Century? Fitness and ability to do the job should be the defining contractural consideration. Shouldn't it?