Holy crap get angry much?
You must not read much here. Vin (devs) posted an idea for ppl to vote on asking if everyone wanted private messages. That was almost 6 months ago. Only 15 or so ppl have voted on it.
Technically, i did not assume you had read Vin's message pinned to the top of the feature request page. I assumed that you did not read it as you are effectively asking for the same thing. Also I'm not sure a wall to speak to all 6,400 plus mobs is something that is going to be of assistance to me or anyone else. How could anyone possible manage the number of messages that would take place on said wall. The game already lags enough. Everyone that has been playing the game for any length of time has adapted to using KiK, Line, Palringo or any of the other chat apps out there. There are numerous chat rooms in each of them dedicated to DTM.