because traffic rules are mostly imposed upon us by force, and we know the immediate consequences of breaking those rules, as it would either take away our life or if our life is saved, violating rules might lead us to jail.
But sunnah of the prophet (saw) is followed by heart, it is purely controlled by “Love and passion for the prophet’s acts”, which doesn’t require imposition or questioning of their requirement in life. Love doesn’t always require logic.
Those who love the prophet (saw) wouldn’t question the intensity of the sin for not following it, but would be ready to give away their life for it, but others would say in a disgraceful tone, " Sunnat hi to hai, farz to nahin. karo to sawaab hai, na karo to gunnah to koi nahin.
Bhai, do jahan ke sardaar ka ishq bhi to koi cheez hai. Har kaam ke liye pehley sawaab tolna zaroori to nahin.
Love of money immediately forces me to pick a 10 dollar note that falls from my pocket, but love of sunnah is not that strong that I would take care and not let it fall from my personality.
May Allah (swt) bless us all towards the right path.