Well, first and foremost, there is no scene anymore. At least not a coherent one. Back in the days, everyone knew everyone, and gaining "entrance" into the scene, so to speak was definitely not guaranteed by just showing up in a cook t-shirt. Now, the "scene" is flooded with left-wing hippies and open-minded people. It is faaaar less esoteric than it once was. And that is just when talking about the metal scene, which, in many ways is a distorted reflection of our whole society.
Another great different, would also be that fifteen years ago, there was actually such a thing as a taboo subject. And that meant that the artists didn't have to make ridiculous gimmicks out of themselves (at least not the same degree as they must today!
), they could just speak what was on their honest minds and could focus on the thing that is vastly more important than image; the music. Nowadays bands strive waaay to much to be noticed. And as we all know, if you want to be noticed quickly, quality in your music won't be on the top of your check list.
Bah, I could probably write a lot more on this subject, but this should cover the more important aspects, I think. If you want to know more, feel free to ask, of course!