Please tell me precisely WHY this is a major news story?

Only because you assert that it is. Nobody else thinks so. I would not have read the story if not for your link, so thanks.

My take on it is that not everyone is as savy as you are about mail security. The story gave some info about what mail is likely to be opened and what is not. I did learn some things that I did not know. In that respect it was a very good story.

Teaser headlines are an ancient ploy to get you to read an article. Man, take a look at all the gimmicks they use on commercial TV to get you to tune in/not switch channels when a show you like is over/keep the channel where it is through each and every commercial...

It is all advertising and entertainment. To you, it looks nefarious when you don't like the content of the story.