Well, this is based on absolutely nothing but my own gut instinct. So just a theory.
But while only Shepard Smith did it outright, I have trouble imagining most FOX News people (Hannity excluding, natch) getting on board with his whole strategy. Say what you will about conservative journalists (and I do), but they take themselves seriously. And I can't help but think that many of them were pulling for Beck when he first came on, but might be starting to feel like he's using serious histrionics as a gimmick, and worse, doing it really badly. If he keeps finding continued success, I can't help but think many of them might start getting that certain feeling when people start saying how much they like their show and Beck's.
Again, just a guess, but I think there might be something to it if Beck keeps on doing what he's doing. And why wouldn't he? Howard Beale has found his angle.