The traditional example is interviews for C coding jobs, where when developers interview, they gravitate towards standards-lawyering type interview questions. That at least has the advantage of being a fairly stable community, though; being a "C coder" has a certain set of cultural assumptions, and it might even be true that if you don't know certain trivia questions, it's a reliable litmus test for whether you're "really" a C specialist.
I am beginning to believe that the majority of people who consider themselves experts or experienced are really just novice or intermediate and don't realize how deep the rabbit hole goes.
I understand that it can be frustrating to feel like some non-technical person is blocking you from talking to someone that you can relate to and prove your value to. But it is just as frustrating once you get to someone technical that can understand you, only to find that that person is using equally arbitrary criterion to evaluate you.
I agree with your point, and posted that job ad in support of it: To disqualify someone because they are using C#/.NET is arbitrary and stupid, and apparently came from engineering.
* The fire storm over Deviant Art's 'we only hired 0.0000001% of people' blogpost/HN discussion.
* I went through the application process at a start-up where they were "really excited" about me after the first interview, but dropped me after the second because of a couple of stupid trivia questions. Trivia questions related to callable classes in Python, a feature that while interesting is (from what I can tell) little-used and extremely easy to pick up (took me 5 minutes of looking at the docs).
* I've seen groups within my own company pass up people with potential because they are 'too old to be junior developers.' (In this case, it was someone with development experience, though not too much, that was changing careers and who showed promise in his interview questions.)
* I know of particular people within my own company that are really smart, but also really harsh on interviewees. The tune seems to be along the lines of, "I'm a rockstar programmer, and if you're not too, then you're an idiot and I don't want to work with you."
* I know of places where it's generally admitted that current employees would not pass the interview process for the job that they do, even though no one thinks that they are inadequate for the position.
These are all examples of developers also doing a horrible job at hiring by finding arbitrary criteria to base their decisions on that have little to do with whether or not someone is a qualified candidate.