Let us not forget that many doctors used to endorse smoking prior to the 1964 report by the Surgeon General warning us that "cigarette smoking may be hazardous to your health". At the time, smoking was often believed to help in reducing stress thusly allowing people to "relax". Considering the high stress environment that newspaper reporters, columnists, editors, etc, faced on a day-to-day basis to "meet the deadline", it's no wonder Herb Caen (et al) smoked so heavily.
I vividly recall visiting SF General Hospital where Dad had his dialysis procedures done three times a week from 1969 through 1975, and seeing doctors, nurses, technicians, orderlies, and patients themselves openly smoking in the clinic. The same was true whenever Dad was hospitalized. His doctors, nurses, himself, and any visitors openly smoked in his room, the nurse's station, or just about anywhere else within the hospital. Sometimes it got a little "thick" at times too. And yet again, another occasional high-stress environment, maybe even more so than the Press Room at the Chron.
I am not saying it was healthy or right, but back then it was an acceptable part of life...and as such, a part of (some of our's) history.