Excellent point! To paraphrase a prominent American, some of the people are stupid all of the time, all of the people are stupid some of the time, but not all of the people are stupid all of the time (fortunately).

I would be curious to know if these foks who blundered were actually looking at a map or were they following verbal directions? I think going in "turn by" mode gives one tunnel vision with occasional unfortunate results. One the other hand, there are folks who cannot interpret even the simplest road map.