I would like to see how the 18/19 year old Virgin Blue Cabin Manager handles this situation compared to the 55 year old Qantas CSM who's been flying for 25 or 30 years.
So how many evacuations or emergencies have those 55 year olds done compared to the 18/19 year olds. ANSWER - probably the same amount -- NONE.
I think a young fit person would be more able to assist in a genuine emergency, whereas I can see myself having to help the 55 year old out the door.
And at the risk of introducing fact into the argument, the majority of flight attendants are not 18/19 year olds.