Well, for one thing, The Moneypenny Diaries series did include James Bond in it. He was sprinkled throughout the book in Guardian Angel, not quite so much (understandably under the circumstances) in Secret Servant, and unfortunately not enough in Final Fling.
Guardian Angel did a good job of filling in the gaps in the aftermath of On Her Majesty’s Secret Service before leading up to You Only Live Twice. Secret Servant fills in the gaps a bit at MI6 before and after Bond’s return from Russia after YOLT and before The Man With The Golden Gun. Bond doesn’t do much, however, as he is largely being deprogrammed, but Moneypenny does have a pretty interesting mission to do, herself. In Final Fling, Bond has one mission assigned to him, but most of the book focuses on Moneypenny’s and her niece’s actions.
Guardian Angel started the series out well, but the it gradually starts losing its luster. I’d rank them as Novels: 1) Guardian Angel, 2) Secret Servant, 3) Final Fling. If you just went by the stuff about 007 then it would be: 1) Guardian Angel, 2) Final Fling, 3) Secret Servant.
But ultimately, no, The Moneypenny Diaries didn’t kill the franchise. Did it dilute it? Maybe a little, but I think there are enough tidbits in between Ian Fleming’s Bond missions that makes it worthwhile (though I have some issues with Final Fling).
Will Quantum Of Menace dilute or kill the franchise? I seriously doubt kill, but dilute? Yes, I think so. The problem I see is that Q will no longer be associated with MI6 and likely have no interaction with Bond either. What worked with The Moneypenny Diaries is that it still had James Bond, AND it was the 007 and MI6 we all know and love. QOM doesn’t seem to have that. And that is the biggest problem with Kim Sherwood’s series. I’m halfway through A Spy Like Me, and while she obviously is a fan of the series and is knowledgeable, there is just too much change and rebooting going on that keeps me from fully enjoying the book. (That, and a lack of James Bond as well.)
So, in short, James Bond is the draw. When he is present, the stories pick up and get more interesting. When he isn’t, something is lacking–although I think Moneypenny did carry her story in Secret Servant. But, overall, nothing can top a James Bond-centric story.