BO (aka body odour) forgivable but cigarette smoke not

Having a BO is not really a choice (although maintaining hygiene and utility of deodorant alleviates the problem), because genetic (pmid 20081888) , occupation and environment (e.g. high humidity) plays a role.
However, smoking is not! Smoking in public is an act of apathy and selfish self-indulgence. I can forgive people with body odour, but I tend to hate senseless smokers.