The TV personality, who worked with Cowell on "The X Factor" U.K. for several years, and served as a judge on his show "America's Got Talent", said the music mogul, "doesn't have an ability to see individuals".
"That's why he turned down Jennifer Hudson, that's why he wouldn't champion her on 'American Idol'," she said on Friday's (April 03) instalment of her U.S. daytime show "The Talk". "But it's the truth. He's very dated (in his views)."
Although she allegedly missed out on Simon's backing and placed just seventh on the show, Jennifer went on to bag an Oscar for her performance in 2006 movie "Dreamgirls".
She also previously shared similar sentiments with Sharon, explaining, "Simon told me I was 'too big' in every way. I think he meant my hair, my voice, my personality, my songs."
"I didn't really understand how that was a negative thing. I said, 'Is big not what a star is?'"
Sharon previously claimed Simon axed her from the judging line-up of "The X Factor" U.K. last year for being "too old" and, despite his apologies over the incident, the TV personality has drawn a line under working with the star again.
"I don't want to work with him," Sharon told Britain's Daily Mirror newspaper. "Because I said certain things about, and to, Simon, doesn't mean I hate him for ever, just for that second I don't like him... He is OK, it's just I don't want to work with him."