Most smokers are assholes and genuinely don't care about stomping a butt and the city is too cheap and scared of homeless people to put out more ashtrays and garbage cans and hire more workers.
I was in the city this weekend and finding a place to put my butt was a hassle the few times I smoked away from my hotel, which did have an ashtray. You'd think they would have those disposal things attached to every bus stop but they don't.
Depends on the bear. Black bears are cowards and you can generally just make noise or act big to scare them. Brown or grizzlies you'll want to play dead and pray then don't try to eat you. Polar bears, good luck, better have one of those boxes really close by.
The rule on black bears can go out the window if they are worried about their young, super hungry, or young and inexperienced with humans.
Someone with better knowledge can correct me but that's what I was taught when I was a kid.