Probably because they're not even in the same category. Someone's weight is just a result of their eating habits or having a lack of exercise, and it's really only a problem if they want it to be. A smoker is deliberately picking up an object and harming themselves and others around them. There's quite a difference there.
In my personal opinion there's not much difference between the two, even obesity can harm others around you... your family for instance? How many times have you watch the biggest loser, and it's not just the dad or the mum who's obese, but the kids, the dog and the friends too? Being fat is just negligence taken to an extreme. there's no excuse. it should be a crime.
as for smoking, it's stupidity plain and simple. you may as well be playing russian roulette with an auto.
also for derpcakes up there, your name rings true. pot causes brain damage. I should know. it's how my father died.
Because sugar and fat are not yet taxed at the same rate as smokes, for the damage they can do to your health?
(BTW: How many thin politicians can you think of?)
Being overweight can kill you just as effectively as smoking can.
I am not anti sugar or fat, just anti "I can't help it, I'm big boned"...
That is self pitying ********.
Change your eating habits, get up off your ass and go for a half hour walk every day, it does amazing things for your health, appearance and self confidence.
Giving up either habit requires you to stop putting the wrong things in your mouth. And given the number of people who starve to death on this planet, eating a whole lot more than you actually need to is just as bad as second hand smoke damage to other folks lungs.