There was a 24/7 janitorial staff; they did light stuff in the daytime and did mopping, shining, polishing the marble, touch up painting and such at night. However, in the newsroom where I assisted with the carting of the newsbriefs each hour, wire copy filled up and overflowed the baskets faster than the folks came around. In my example, I offered to clean up the spillage and was told in no uncertain terms that doing "that sort of thing is stuff we don't do". Despite being an intern, I was part of the programming team, not a part of the cleaning crew.
No, as I said, this was a societal value prevalent at the time that said that a person who is at a certain level... or even more so for someone who had risen to a certain level... did not do work that was "below" them as it projected a wrong image and indicated to others that you were really not suited for your current position in the food chain.
I did everything from helping to cart newscasts and taking them to the 5 stations to doing song edits, and even got a "temporary dispensation" from the powerful union to learn how to board-op for the DJs. I was seldom sitting, and probably did 25 different things throughout each day.