Confirmation bias. Once you have an opinion about a guy, you only want to see what fits the mold you have made for him. It's understandable because it's human nature, and I think even the most dead set for or against these guys can agree that all of them are reasonable candidates, even if none of them are ideal.
Once you've decided that you like or dislike a guy, it's tough to look at the other side of things with an open mind. So McCoy sucks because he ran the Foxball offense this season, Philbin sucks because he's never called the plays, and Bowles sucks because he looks like a freaking wax statue on the sidelines.
On the other hand, McCoy is great because he had the #1 rushing attack (by far) despite his awful QB allowing teams to load the box against the run. Philbin is amazing because he's from the Packers and he could install that great offensive scheme here and maybe even raid their coaching staff. Bowles is great because the players love him and there would be some continuity.
None of these guys set my heart on fire, but I don't think any of them are bums. That said, I'm going to completely freak out if Todd Bowles winds up being the pick. I promise you that.