I am old enough to remember when people smoked everywhere (almost). Flying as a kid I can confirm folks smoked on the plane. I think the only places where it was not allowed were in court rooms and church as a matter of etiquette and theaters where it was very strictly prohibited by fire codes. Your gramps must have come from the land of long ago if he can remember being allowed to smoke in a theater.
We had a four pack served with dinner on China! Couldnt light up in front of parents, but squirreled away for later ( only 12!)
I remember smoking in theaters. I knew a man who sat in the front pew who smoked.
I’ve smoked many cigarettes on airplanes. Some plans still in service today have ashtrays.
Kinda like when they decided to classify the AR-15 as an assault weapon....incrementalism.