Lord Sugar's sidekick, who recently became the new presenter of Countdown, questioned Imogen Thomas's position in the public eye following her affair with Ryan Giggs.
"Now she's giving out bloody prizes at awards ceremonies? What is her talent? What is her value?" Hewer told the Sunday Mirror.
"Fame and celebrity for doing nothing is very seductive to very stupid people. Sleep with a married footballer and you are a celebrity. Where is the value in that?"
Speaking of his own fame, he added: "I have had one marriage proposal in my time on TV, but it was a rather scary one. It was a card, and when I opened it confetti fell over me. Inside it said, 'Marry me, marry me, marry me'.
"It was terrifying. It reminded me of The Shining. And there was some woman's telephone number. I didn't call her, but I kept it in case I was found slaughtered in the street."
Countdown ratings have risen since Hewer took over hosting duties from Jeff Stelling, but he laughed off suggestions that he has become a sex symbol.
"Have I attracted a female following? Well, I certainly hope so - but I would react with astonishment to being told I was a sex symbol. I'm nearly 68 for God's sake. I know I have been called a Silver Fox. But I don't precisely know what one is."
Hewer, who was encouraged to accept the Countdown job by Lord Sugar, recently admitted that he was nervous about his debut on the show.