I'm inclined to agree with you diagnosis. But here's a thought: if she's that good when doing half a job... How much more would she sell if she focused on the job at hand, rather than promoting her personal projects on QVC's, the brand's and our dime?
Back in the day I used to be pleased when Debbie was presenting; she knew her stuff, focused on what a customer needs to know... Always went through sizes and important information... Then she morphed into this arrogant self serving behaviour which is such a turn-off.
By contrast you have mainly male presenters who still bother to prepare for shows; take the trouble to look smart; and ask the questions we would want to ask. I like Miceal as an interviewer particularly... He did fantastically when they had Jimmy Connors on one time... It gave me quite a different perspective on him.