Dire Bare
Legend
But, but, but...the game was everywhere back then, from middle schools to college campuses. I was denounced in churches, and had its own cartoon! It was huge!.
As others have posted, D&D had a higher visibility in pop culture in the 80s than it does now. But that is a different thing from the number of people who are actually playing the game and buying new books. The audience for all the various D&D novels over the years also overlaps but does not equal the audience that plays the game. I had friends when I was a kid in the 80s who LOVED the D&D cartoon and had some of the toys . . . but didn't even know it was all based on a new kind of game called a roleplaying game. Just as I have friends now who love reading the latest Drizzt book but have never rolled a set of polyhedral dice . . . conversely I have grognard rpg friends who despise the D&D novels despite never having read any since the original Dragonlance trilogy.
And part of the reason why we don't have a D&D cartoon and D&D toys and merchandise today is that TSR was not a good student of the Lucas School of Brand Marketing (Star Wars, dont'cha know). The D&D brand was not well managed and died the quick death of a fad . . . but the niche hobby of roleplaying has slowly and steadily gotten larger and larger over time despite that.
I think the folks who persist, despite common sense, to claim D&D 4e is not a success, is not selling well, or that there are less players today than yesterday just can't accept the fact that their individual tastes regarding D&D aren't necessarily shared anymore by the majority of roleplayers. It's a lot like music geeks who love obsure bands . . . but if the bands somehow find commerical success they instantly become "sellouts"! Loving the obscure and inaccessible is part of their identity.