When I was interviewing software developers in the 1990’s, it was very common that people would apply that could not code at all. I don’t think they were nervous or that the question was unreasonable. We were a C shop and the question I opened with was in K&R and just a simple question about arrays. Many candidates could not give any answer. I wasn’t the only one seeing this, which is why FizzBuzz was created.
These days, I hardly ever see that. Nearly everyone I interview can code and can answer the simple questions. Many can answer any reasonable question. This means that we often had more than one good candidate.
But we still had only one job.
The problem is similar to what I wrote yesterday about layoffs. You might need to layoff a person you would hire if you had the budget. In both cases, that person is not really rejected, they just didn’t get picked from (what was probably) multiple good options.