Don't say the "Z" word

I've noticed that in both the stories we read for last lecture, as well as in most other zombie related works that have come out recently, the authors seem to go through pains to never mention the word "zombie". Instead, they are called "freaks", "monsters", "infected individuals" and the like. I wonder if this is because the authors want their works to be respected in the literary world that they distance their stories from the campy, B-film zombie movies of the '80's. Zombies have become so common in modern media that the average reader of audience member probably doesn't treat them differently than any other science fiction or supernatural genre. In that case, avoiding the use of "zombie" to make a piece more serious is probably a ploy to gain the respect of critics and academics. This is just a small part of the issue of science fiction / speculative fiction not being taken seriously, or even dismissed off-hand, in the literary world, something we know Ursula Le Guin struggled with with many of her works.

Interestingly, George Romero never used the word zombie in his ground-breaking "Night of the Living Dead". But if this didn't popularize the word "zombie", then when did it become widespread in the public lexicon? Or was zombie already a word to avoid by the '60s?