The traditions and ethos of the British Armed Forces include lining up and walking slowly towards machine guns, building accommodation out of toilet rolls because none has been provided and generally being silenced by politicians when they can't afford to fund us properly.
With the BAFF making it quite clear they'll not interfere with machine gun tactics etc, that leaves them representing us on the latter 2 points. Of course there's no tradition of British Forces being represented, but you could also argue that creating such a body, to raise legitimate concerns, might prevent people leaving in such numbers, even at a time of economic downturn! Moreover, if we've never had it so good, as some ministers claim, the government have nothing to fear from the BAFF.