So many reasons I don't smoke inside, in no particular order:
1) I have a daughter and don't want her smelling like smoke or inhaling smoke.
2) My wife is allergic to smoke.
3) The resale value of a smoker's home is considerably less than a non-smoker's home, all things being equal.
4) I don't like the smell of stale smoke on clothing, furniture, etc.
5) Smoking inside gives me a headache. To be perfectly honest, there are few B&Ms that I will smoke in.
6) I like being outside.
The list could go on. The only time that I would ever think of smoking inside my own home is if I had a separate structure (shed, detached garage with an upstairs, etc) and it had a kick-a$$ ventilation system. Sort of like a man-cave that isn't part of the house.