Just my opinion, but I doubt anyone is actually "benefitting" from smoking.  You're taking it into your lungs, blood stream, blah, blah, blah.  That being said, I don't think a few a day is any more harmful that a few drinks a day.  But as you said, cigarettes are the bogey man.  You can still drink on airplanes and have to put up with drunks on the road.  I've heard of people being drunk and harming their families, but I've never heard of anyone having "one too many cigarettes" and doing the same.  Go figure.

*Kat