Are they, or are these relatively new hires? What you point out might explain the 60 year old ladies. It doesn't explain the 35 year old gay guys. To be perfectly honest, I don't care. Like any other guy, I can appreciate attractive women, but I'm not looking to pick up flight attendants or to join the mile-high club. Competence and courtesy are my concerns. Whether I'm given that bag of pretzels by a hot chick or by the washed up keyboardist from the Pet Shop Boys is of little consequence.
However, the contrast is pretty stark and hard not to notice. The occupation formerly known as "stewardess" used to be dominated by courteous, attractive, younger (maybe 25-35 year old) women and still is in most nations. Then in the US in around 1985, the profile started to change to pissed off 50 year old women and their gay nephews. It's just kinda strange and also noteworthy that it's almost entirely an American phenomenon.