In the beginning of man’s quest to control fire (a process apparently not yet complete) he learned some beneficial aspects of the stuff.
Ogg (names were simple then) noticed that if he built a small fire and kept the temperature low and contained the smoke in a defined area for an extended period of time, it did wonders for the preservation of the meat of whatever poor critter he'd managed to fool that day. (Unfortunately, that is a job he's gotten much better at).
How could any being capable of critical thinking possibly think doing the same process within the confines of his lungs would not cause any problems? I'm ever so sorry about this chief, but I've just got to add “duh” here.
The folks that Sir Walter Raleigh first observed only used the stuff for celebratory events. Or maybe they understood, "Every man that striveth for the mastery is temperate in all things."