Except that lots of errors are already known, and get repeated anyhow. Saying that we can't guard against unforeseen errors is not quite the point.
Errors we already know about are known because they are common. Preventing those errors is a net win, regardless of whether unforeseen errors will occur.
Errors we already know about are known because they are common. Preventing those errors is a net win, regardless of whether unforeseen errors will occur.