I think public pressure is always a factor though. As is reputation. Neither Hector nor Kennedy have the brand-name, all-star closer pedigree that allows a manager to stand by them no matter what. I also strongly suspect that Middleton is the kind of owner who would actually call the GM if the closer pisses him off multiple times (not a huge stretch considering he personally fired the hitting coach two years ago, though one assumes Dombrowski and Girardi get more respect).
I also think any reliever can have a bad two weeks or a bad months, but when that month is August or September - which was also the case, by definition, last year - you can't wait for them to ride it out, right?
Remember when Joe actually went back to Workman for one game last year in September? Oy.
I generally don't worry about it because I think any of these guys can lose a game for us between the 6th and 9th inning right now (as Brogdon did on Wednesday). Obviously it hurts the most in the 9th.