Having worked down 'the back', I have asked this question myself to so many cabin crew, those that genuinely love the airline lifestyle see their careers going in the direction of being promoted to a purser/no.1/cabin supervisor, then a training role rather than moving up front, to some it may seem as natural career progression to others it may seem as lack of ambition.
The girls that I met during my CPL/ATPL courses all had previous hostie experience and were very determined students but if something was not working out they did play the simpathy card, and too often many blokes fell for it!!!!haha
Having said that, none of them are unemployed now, and so I say good luck to the lot.
Ability has nothing to do with gender etc. we are all here on or own merits and ambition.