Eh. There are those who will tell you that rock and roll was always kid-stuff. But it wasn't. Ike Turner and Roy Brown were writing songs for juke joints, not sodd-Y shops full of babyboom rugrats.
That was Leiber and Stoller doing their take on the hep sounds.
Big Mama Thornton's biggest hit may have been Hound Dog but what she did before and after that sound nothing like it.
And even then Elvis' hit had even more toned down lyrics.
Rockabilly was a barebones sound, but those songs were rockers. No more big bands. No more heavy production.
RCA had to try to duplicate the Sun Studio "echo".
Garage bands and later punk/new wave/post-punk/no-wave bands didn't have the luxury recording situations or need to play the "arena rock sound" with 5 minute solos while the audience sat on their hands.
Every generation tears it all down and returns to basics again.
It's the pop faux-rock that kills it. Grunge was the last gasp of a music industry that would take something that's growing a following a put it on radio to see what sticks.
After the canon was codified, the public was force fed a steady diet of poster idol pop singing groups (NSync, Britney, Christina, et al). Happened in the 1980s too (New Kids, Menudo, Paula Abdul...). Happened in the 1970s too (Osmonds, Leif Garrett,...). Happened in the 1960s and 1950s too.
Jerry Lee Lewis was interviewed for the documentary "All You Need Is Love" and had to laugh. He'd been shut out of radio/tv/movies after his scandal (and after the other stars had been jailed, died, drafted, or shamed into retirement). He said all you had left were a bunch of Bobbies. Bobby Vee, Bobby Vinton, Bobby Darin, Bobby this... He said that the Beatles sure changed their game.
That grunge and punk/new wave history is the real lineage of rock and roll. Bill Graham wasn't a friend of rock.
But not this last one. The last ten years of "Pop" has seen the most un-listenable, gimmicky crap every composed. It's Broadway tunes-meets-Vegas; Been like eating at McDonalds every single day.
In my subjective opinion, the only area that's improved - and substantially - has been contemporary Country - yes, Country. It's at least attempting to recoups Rock's original cues, riffs, and trademarks.
Look - 95% of all Rock basics from the 1950s till now are nothing but simple three chords. It's why everything seems "derivative." But in any case it's what naturally sounds most pleasing to most ears.
Everything else are that core three-chord is just variations, embellishments.