[TSAdmin]

Playerworlds need to optimise their use of player.communityName and the findPlayerByCommunityName() function.

Down to the business end of it though, accounts are not (and will not be) renamed. All information stored anywhere is associated with your account as a referencing factor. Renaming your account would pretty much reset everything that makes your account.
Eg: Your gold subscription (Which is associated with your account) would no longer exist, all your attributes on all servers would not exist, all your profile information would not exist. It would be as if you were starting the game entirely from scratch.

The above, as a whole being categorised as "Totally reset" if a name need be put to it, is only one reason accounts are not renamed.