Yes he was such a bad sax player that he could sell out 90,000 stadiums 4 days in a row with his band. He also was part of selling a crazy amount of albums. He couldn't play a major scale? Are you for real? Go play your sax in your house telling people he can't play like you can. Keep playing do re mi with your woodwind in your delusion. Grover Washington Jr. and David Sanborn both had good things to say about Clarence. I never heard them say you know that Youngblood could play a major scale really cleanly. Where did you ever hear him play scales?
One- I'm not a sax player, and you don't need to be a sax player to understand whether someone can play their instrument or not.
Two-the major scale when used properly is not just do re mi fa so la ti doh. That is but one combination of possibilities. I have not heard him play scales as a practice, but if you pulled your mouth off your asshole, you would understand when you hear someone play (especially in pop music) they're playing the major scale over and using a different combination of those notes making up the major scale.
Three- just because you're selling out stadiums one night in a row or 4 nights in a row does NOT mean you yourself is talented. Michael Jackson could sing, dance and put on a show. Brittney Spears can dance and shake her tits, and put on a show. Clarence could shake his tits and put on a show. But that point is irrelevant to what I was saying...I was talking his playing. Because he shakes his tits does not mean he is any better of a player than someone else and should be selling out stadiums.
When you get to the level of being a star, playing stadiums and filling them up, music is the last thing that needs to be there in order to be famous. Image, dance moves, song writers producing good vehicles for you to butcher, proper promotion and advertising and last is being able to play music.
Over 3/4 of the music you hear on the radio today can't be reproduced live because the musicians are so talentless that it can be, and is, doctored up in the studio. Beyonce was in the studio once and she couldn't sing, so they spliced her tape from multiple takes together to make a song for her. Slash was so strung on heroin that his playing on "Welcome to the Jungle" is barely on it because he was in the corner nodding out and the studio had someone around to play similar to him...so it's him and Slash is barely there. Paul McCartney played drums and guitar on some Beatles albums, Hendrix overdubbed Noel Redding because he didn't like his playing on the last album. All that shines ain't gold.
As for your point about Washington and Sanborn, that's moot. They're big names yet if they trash him they could lose album sales or audience. They could have been (not saying 100% they were) saying that to be diplomatic or politically correct. Again, don't believe everything you read.