In short, airlines don’t trust passengers to not light up, and, contrary to opinion, they are not there as a sign it’s acceptable to smoke.
A Cathay Pacific flight attendant told TIME: “You’re not allowed to smoke, but some people still do it.”
The cabin crew member even revealed she catches somebody smoking about every six months. “So if you do smoke there has to be a safe place to stub it out,” she said.
There are very strict industry rules in place concerning ashtrays, too.