Being a surveyor, I search for benchmarks quite often, many times with no results. It would be nice if more surveyors would report their findings (or lack thereof) to the NGS, but most don't (including the company I work for unfortunately) so the benchmark I looked for last week, and didn't find, may have been 'not found' by 20 other people. Therefore I find benchmark hunting rather frustrating. Besides, I like actually finding a cache and seeing what kind of stuff is in it!
PS - I have considered reporting my benchmark finds the the NGS under the GEOCAC agency code, but I haven't done that yet. If anyone else wants to do this, just note that the NGS has very specific standards for benchmark reporting.