Comment by auntad

I'd suspect a valid correlation that's not a causation. If a company is generally doing well, presumably the CEO isn't under as much stress and doesn't have as many firefighting responsibilities as those whose companies are doing poorly. Hence having the time to write a letter to a stranger.

Maybe those underperforming companies will bounce back and you'll find a (much delayed) response in the author's mailbox a few months down the line!