They are certainly critics, but in this case, I think more for the shock value than as a matter of knocking the current administration.
The problem with that, IMO, is that a terrorist could presumably act in a similar way.
Both the media and the administration share the problem of promising or demanding perfection, absence of error that results in innocent loss of life. Security in a public setting is particularly difficult, becuase people prefer to think they aren't being managed that closely. Face it, mitigation of terrorist threat, or just plain "bully threat" even if not part of organized terrorism, has a price. There are many factors to balance out in that calculus, but no matter where the balance is struck, innocent people will be killed - either by bad guys, or by friendly fire.
In the current paradigm, all you or I have to do is follow orders, and those in charge will minimize casualties.
... the Marshal made a split-second decision that--to be honest--I'm perfectly okay with.
I'm ambivalent. I was ambivalent with the guy in London too. At the same time, I am pretty sure there will be no watering down of security, and no admission of error.