It's retarded as someone who want to make Twitter profitable. He's taken a globally established brand. Everyone who isn't in some 4th world toilet knows about twitter and the blue bird, and he has instead decided to replace it with the most generic, most boring, most overused "this is cool" brand name of X.
-Xmen
-Xvideos
-xXx (the Vin Diesel movies, not the other thing)
-SpaceX (coincidence? The autist likes that letter).
And so on. Tweets are no longer tweets, they are "Xs". This is like a retard's idea of what a cool rebrand is like.