There's a difference between being a straight-shooter and being too blunt. A straight-shooter would say "your performance isn't where it needs to be, you need to improve". Someone who is too blunt would say "You f*cking suck, get better or I'm cutting your *ss". Now, on average, which one is going to get the better response from his team? If anyone says the blunt guy, you haven't taken any psychology courses, ever. Whine and cry all you want, countless studies show that positive reinforcement is the best way to get the most out of someone, and it's not even close.
I'm not saying that's how Zimmer is. I don't know the guy and I doubt I've heard say more than a few sentences. But, if he comes off as someone like that, someone who risks losing the locker room because no one likes him, you can't possibly blame Ross for not going that way. It has nothing to do with insulting the interviewers, all though that can't help matters if it happened. You always hire the guy who is going to get the most out of the players, and it sounds like Ross has at least a rudimentary understanding of psychology and business, both of which are more involved in an NFL team than most realize...