Some people do, of course, believe that the TSA has literally never caught a weapon. Some people also believe that the TSA is secretly protecting us from the lizard-men from Mars. It is fairly easy (even here) to find someone on most any side of a debate who's arguing from deranged criteria.
We can argue about what qualifies as 'standard' - although I don't think any of us have access to much in the way of quantification regarding arguments for and against the TSA. Proof to the contrary would be a pleasant surprise.
I hope it suffices to say that most people who are concerned about the TSA are concerned about rates of detection and perceived effectiveness of techniques versus cost. Even if not everyone would be so wordy.
http://disinfo.com/2012/03/has-the-tsa-ever-foiled-a-terrori... (blogspam about an economist article written by Bruce Schneier about the TSA never catching terrorists. Bruce Schneier is likely the most prominent person that points out that the TSA never brags about bagging one. I would wager that he popularized the point.)