I'm not sure whether any of my knitting has been ripped by this channel as it's a new expression for me.

Curious title for the video, it seems to be more a random list of alleged miscalculations he made. I say "alleged" as I thought that Berry Gordy was keen to sign The J5 once he saw them perform at their Motown audition and, as far as I'm aware, he was keen to hang onto The Supremes (or at least one in particular) in the months before "Where Did Our Love Go" broke the group. Funnily, I believe that he was seriously thinking of ditching Stevie Wonder until "Uptight" revived his career, but there is no mention of that in the video!!
Two errors I noticed were that the J5 had had a single released before they were signed to Motown so "I Want You Back" wasn't their first, though their one pre-Motown 45 was only released in The Chicago region. The other was that it states that The Isley Brothers had recorded "I Heard It Through The Grapevine" ... did they?
I disagree about Rick James John ... he was hugely popular with the Soul/R&B crowd in the late '70s/early '80s ... he seemed to be creating trends at that time whereas most of the other Motown acts were following them. If his popularity wasn't properly reflected in the mainstream "Pop" charts that's probably because mainstream radio had turned away from hard-edged R&B on both sides of the Atlantic.
Regarding Gladys Knight, not only did Berry Gordy not fight to keep her it seems that he didn't even know that she was leaving as it has been reported that when "Midnight Train" reached #1 in the USA he thought that it was another one of her Motown releases. Presumably by that time he had stepped back from being part of the "Quality Control" team.
Roger