Well, 60 minutes was as mainstream as it gets, but I remember it being aired on network news, it certainly made its way onto day time talk shows. It was not just the 60 minutes program. And you had TV movies like Mazes and Monsters, the book it was based on. You also had a ton of religious programing about it (which people can dismiss as fringe, but stuff like the 700 club and Jerry Falwell had considerable cultural pull in the 80s). I believe i even posted clips I found from old news shows here and elsewhere in previous threads (but I can't recall exact programs off the top of my head). And if you go beyond D&D, into music and ritual satanic abuse allegations, that was on pretty much everything, from the nightly news, to daily talkshows and more. But again, just pointing to my own experience of guidance counselors who expressed grave concern about D&D, and people I knew who were in therapy where that was the source of the household ban (not religion). I am not saying it was satanic panic all the way down in the mental health field at that time, but you had all kinds of people testifying in court cases, appearing on TV and showing up in peoples daily lives who seemed to believe there was a potential issue with the game.
Again, I am not claiming my memory is the sole arbiter here, but what I recall from living through it, is that it was quite mainstream for a number of years (and obviously some of that is going to be regional: there was a lot more Satanic panic when I was living in the west coast than I encountered living in the east coast---but the panic was also dying down by the time I moved back east so not sure how much of an impact that had). I think people also tend to forget how religious the country was in the early 80s. I also think people tend to forget how conservative the mental health field could be at that time too.