Two names are cumbersome.

[AceofRains]

Two names are fine by me. Maybe and Option to hide your last name if it bothers you that much? I have no problem quickly typing a player name, It shouldnt be if you know how to actually type, even better if your targeting the player just put <t>. Btw let me bring your attention to the 2.0 official screenshot. Notice the last names are abbreviated in the log. i.e: Delita H. or Yuffie K.

Plus many NPC's call us by our last name such as in the Grand Companys, as its a kind of military deal. Last names are part of the game so I wouldn't expect a "One name" function.

And for all people who have something against other peoples names

Beauty is in the eye of the beholder my friend, your name looks just as dumb.