Farts dissipate. Sure, they sink to high heavens for a few seconds; but stale cigarette smell reeks for weeks. Farts do not get in your hair, your skin and your clothes. Farts don't get into the carpet and drapes, discolor the paint on the walls, or make the white ceiling turn gray. You don't need to have your clothes laundered, your hair shampooed and your body washed after someone farts. But, you certainly do when you are around a smoker.
Smoker's typically don't notice the reek in their cars, their hair, their clothes or thier body from their smoking. Much like an athelete may not be aware of bad BO. Do you think that non-smokers are gagging, and making comments to smokers because 'they are out to get you'? Typically, not. Most non-smokers couldn't care less if you smoked cigars, rubber tires, or rotten eggs. The fact is that most simply don't care what you do to your lungs; we are talking about "total apathy". Give yourself 'Black Lung' for all we care. What we DO care about is having to smell stale smoke.