Rock isn't major portion of what I listen to.
I've just mentioned types of rock, but mainly jazz is dominating my collection and far not 60's jazz. Most of it is 80's ECM, CMP, WATT and other mostly European labels so for me, I refuse to agree that music began to decline after 1973.
If I compare 50's r'n'r or rocky-billy than 80's punk-a-billy, punk and post-punk, industrial, indie is far more advanced and interesting so I believe that music started to evolve to more sophisticated scales in 70's 80's from boring and traditional stuff.