I'm afraid r3please that it is part of our culture to shorten sentences and phrases.
You would hear something like 'What she do?" and the answer "She's Cabin Crew"
At the same time you could say when asked what you do for a living "I'm Cabin Crew" or are you going to apply for the position as Cabin Crew?
It's not part of our language that I like but it's there.....part of it probably because flight attendant sounds so sterile or politically correct you don't like saying it....