Ugh this society with tipping is out of control. Im offended when I see a tip jar at Starbucks or the car hop at the Sonic expects a tip. You hand me a drink is not a tippable service, it's called doing your job.
The worst is Marriott's tip envelopes at their hotels. Why would I be tipping them to do their job? My room is almost always made when I leave during the day, there is 1 towel on the floor to be replaced, and all of my toiletries are neatly laid out on a towel in the bathroom.
The craze of American corporations "charging customers the same" but shifting wages onto customers through tips is insane.
And to keep this relevant to the topic, airline employees are absolutely forbidden to take anything of value. AA has a VERY STRICT HR policy (for ethics) that forbids any cash gifts (or gift cards), and incidental value gifts to I believe $20. For good reason. There's a very slippery slope from a small tip to an outright bribe.