Earlier quoted context omitted.
> You can't take one tragic mistake or bad-apple cop and draw conclusions about the fate of the country from it. As per a sibling comment: > The bad apples metaphor originated as a warning of the corrupting influence of one corrupt or sinful person on a group: that "one bad apple can spoil the barrel". Over time the concept has been used to describe the opposite situation, where "a few bad apples" should not be seen…
Regardless of all the rest, what a saying meant 1000 years ago is irrelevant. I find it bizarre anyone is providing historical usage as if proves something. You could pick endless words and sayings in English from 1000 years ago, which are entirely different now. So what? The modern usage is quite clear.
Perhaps it is "clear", but it may have lost the lesson of the original adage. Perhaps that lesson is worth knowing.