Well, in the context of this discussion I interpret 'written for everyone' as 'author was aware that everyone can read this and still wrote what he wrote'. An

Well, in the context of this discussion I interpret 'written for everyone' as 'author was aware that everyone can read this and still wrote what he wrote'. An author of a paper on string theory published on arxive is aware that everyone can read it and almost no one will understand that except for a few from the intended audience. He or she is fine with that and so does everyone else. The authors of the resignation letter are similarly aware of the publicity, but decided to go ahead with their vague and unsubstantiated accusations and their appeal not to believe if the accused party says anything. They are aware of the effect and are fine with that. Some people are not.