What would you suggest instead that would decrease the false negatives without allowing the false positives to explode? The parent poster named a couple of different things s/he tried that didn't work.
Sometimes the best available option is mediocre. ("It has been said that democracy is the worst form of Government except for all those other forms that have been tried from time to time.")
You make a good point. In practice, we've not found a reliable way to weed out the false positives that result (I would not characterize it as an "explosion", but there are definitely some). However, we've stuck with this process because we firmly believe that the benefits of having the excellent people we've hired who would not have passed a standard interview outweigh the costs of getting rid of the others.
Sometimes the best available option is mediocre. ("It has been said that democracy is the worst form of Government except for all those other forms that have been tried from time to time.")