I've lost a lot of respect for Alton Brown and Robert Irvine (I've never cared for Giada, so haven't seen enough of her shows to know whether I respect her talent or not). I still can't get over they're saying that Nikki lacked food authority when Rodney couldn't even get his pie dough cooked. A part of authority is getting the job done. Rodney's credibility as food authority in my eyes, is pretty low. I think I can cook better than he can, so I won't be watching his show.
IMO, you have to start with the talent. Yes, the host has to be relateable and watchable. That can often be taught (David Bromstad on HGTV is a good example of that).
Maybe cutting the FN execs Bob & Susie out of the loop for much of the season was a mistake. I'd like to think that they would have reached different decisions.