Suddenly the visual mattered, and lots and lots of artists didn't care for that. You know how the story from that book was ruined when someone tried to make it into a movie? Well, it's the same thing here. Some things are just better left to the ultimate place of creativity - the imagination.
Artists that had been putting their heart and soul into creating music had to worry about making the video. They had to worry about how they looked, how they danced and acted.
I'm not so old-school to think that music videos ruined anything (not at all), for some artists it exponentially expanded their reach (Michael Jackson's "Thriller," for starters).
Either way, it did change things.
And isn't it interesting that MTV and all of the other "music" channels rarely play these videos anymore? No big point to prove here, just a fascination for how things that are so important one day are seemingly meaningless the next.
And here's one of my favorite "meaningless" videos (definitely joking; this one means a lot to me). Enjoy.
Guns N' Roses - "November Rain"