Because bloggers and journalists are real prima donnas about how they get their pitches. If you don't pitch it exactly the way they want it, into the trash bin, real or cyber, with your story.
Now small businesses and start ups, the ones most likely to have actual news, don't have time to keep up with everyone's personal preferences. That is why they need a PR agency with experience with traditional and new media. But from a reader's point of view it isn't very edifying and if I were a technology reporter I would repress the urge to explain how to kiss up to me and the necessity of doing so.