EyeSeeYouDoesn't the wind blow NOBODY any good...?
To answer this differently, yes. The wind blows nobody any good if it is a
truly ill wind. The statement leaves out the idea of "truly".
An ill wind blows bad things. But suppose that, mixed in with the bad things, there are normally a few good things. But what if the wind is really, really an ill wind? Then it would have no good things mixed in with the bad.
So the statement says: It would have to be a really, really ill wind if it blew no good to anybody.
More clear now?
CJ