This has been my experience as well; It's as if every company is looking for a unicorn programmer... when their domain isn't any more or less unique than any other domain.

One of the "interesting" side effects is that it seems like interviewers are starting with the assumption that the person interviewing is an idiot who knows nothing and then works from there. So any slight misstep or misremembering of something puts you the fail box immediately.

My theory is that part of this is the broken culture of interviewing that we have as an industry. This "tricky CS puzzle" crap that originated at GOOG and MSFT is so prevalent that it's nigh impossible to actually succeed. More than once, it's obvious to me that the people DOING the interviewing couldn't pass their own interview...