I am sick of this "if you don't like it there's the door" attitude.
Working as Cabin Crew is great but there are a lot of airlines who spoil it by this type of mentality. To be a good manager you should be able to motivate your staff and not rule them with a rod of iron, people will be resentful and it will reflect in the attitude of the crew and down to the service for the passengers.
Cabin Crew managers need to learn how to manage people
and get the best out of their staff, not the worst!