DeanBaldwinMusic on TikTok is the master of rock history, having in-depth clips about artists, influences, techniques and eras. In one of his most recent creations about the rise and fall of MTV and why music was phased out of “Music Television”.
To summarize Dean, when top 40 music videos began, everyone was on the countdown. The genres were all over the place, so you most likely got to listen and see your favourite band or song no matter what you wanted to hear. That applied to rock, pop, r&b, easy listening, etc. As time went on the genres in the video countdowns started to narrow down the genres. So if you were a fan of those genres that were not mainstream had no reason to tune in anymore.