You just read about dozens of people being killed by an on-board fire and you’re going to say there’s no danger from casually having a fire on the end of a stick? Even if this one wasn’t started by a cigarette, they certainly can cause fires.
Smoking on flights sucked. The whole cabin ended up hazy and choked with smoke. It stank. I hated those little ashtrays full of nasty ash and gum in the armrests. There are more than just the obvious safety reasons to ban it.
It feels pretty obvious that discouraging fire in a fully enclosed space would have safety as a motivating factor, so I'm surprised that multiple people here are arguing that there's no safety component.
You've got multiple sources of pure oxygen on board, and potentially hundreds of passengers counting on a safe flight in a metal tube hurling through the sky thousands of feet off the ground at hundreds of miles an hour.