It was part of the culture in the 1960's, and only started to change somewhat during the 1970's. Everybody had ash trays, even in non-smoking households, so that you could bring them out for guests. Nobody gave it a second thought. Clay ash trays were common elementary school arts & crafts projects.

One of the things that reminded me of how much a part of the culture it was, is when we visited the Computer History Museum. The SAGE system display had several operator consoles -- each with an ash tray and an automotive-type cigarette lighter in the panel.