I like people who are opinionated, and/or have a point of view. But The Beatles the WORST musicians in the world? Jones has obviously never heard The Shaggs ;-) . It takes advanced technique to play Jazz really well, other musics not so much. Just like in the world of automobiles, it’s a matter of "horses for courses". A 4-wheel drive Jeep is great for off-roading, but you wouldn’t want to drive one across the country. And a sports sedan is great for cruising down the Interstate, but you’re not going to go camping in one. What makes for superior musicianship in one style of music is not necessarily what does in another. What makes George Harrison’s little guitar break (commonly referred to as a solo, but in this case it’s not actually an improvised solo, but more a "song part") so incredibly musically delicious has NOTHING to do with the technique that Jazz guys are listening for in their effort to access the talent of a musician. Those Jazz "rules" are inappropriate for Pop or Rock ’n’ Roll music---they don’t apply. Quincy Jones, for all his knowledge and talent, is apparently ignorant of that fact.
Guys who came up in the world of Jazz tend to think that all music can be assessed in comparison to it. When Buddy Rich was in the hospital the last time, a nurse asked him if there was anything he couldn’t take (meaning medicines, of course). His reply was "Yeah. Country music". Pretty funny, but I’ll bet he never heard Jerry Douglas’ dobro playing.
Danny Gatton was (R.I.P.) an amazing guitarist, and the music he made got tagged with the label Redneck Jazz (and it’s the title of one of his albums). He liked guitar players who came before him from all styles---Hillbilly, Rockabilly, Rock ’n Roll, Blues, Jazz, and everything else. He was no Jazz snob, yet could play that music as well as any guitarist you can name.
I see musicians my age doing nothing but bitching about current music, how it all sucks. They don’t remember hearing "their" music (1960’s, mostly) denigrated the same way by the WWII generation, who pined for the days of the Big Bands. It comes of ignorance, partly. If you don’t understand a music---what makes it work, what principles are involved, you aren’t a person who is qualified or entitled to judge it. And besides, it isn’t being made for you, any more than that of The Beatles (or anyone else of that time) was for fans of Big Band, Jazz, or Classical music. There’s a lot of good music being made today in all genres. It can’t ALL be on the radio, or performed at half-time. The music business is going to push what it wants, so if you don’t like that music, don’t listen to the radio or watch the half-time show.
As for Quincy Jones’ opinion on ANYTHING, I couldn’t care less.