It smells terribly, exposes others to negative health effects without consent and is one of the biggest causes of littering. Simply put it is a major nuisance with no benefits apart from profits for the tobacco/drug industry and addicts getting their high.
Could probably extend that to anywhere around minors in general too.
A small minority of some smokers are the only ones who find that unpopular. It smells like shit and makes me cough immediately. I’m an ex smoker too and can say I’m an asshole for ever subjecting others to cig smoke