Why do I need to change my charactor name during a server merge? [closed]

I have played many on-line MMORPG games and almost all of them have, sooner or later, a server merge. Server merges are performed when (as people quit a game) specific servers have too few players and so the game developers move all the players on an under-populated server to another server.

The problem (from the player point of view) is that if a game character has the same name as one on the other server one of them is required to change their name. When a new character is generated, these games usually only reject names that are being already used on that server.

My question is: Is there any reason (other than programming complexity) that these games don't have a centralized list of all names on all servers?

Using a centralized name list like this would mean any names would be unique across all servers, and server merges wouldn't force players to change names.

Note: apparently there is no general tag for "MMORPG", RPG", or even "Online" so I have added tags for the MMORPGs I have played.

Best Answer

Using a centralized list would limit the amount of names for every player: The likelihood, that one name is already existing gets higher.

Beforehand those server merges are probably not intended and so this name change is done as a compromise.

Just an assumption by me regarding programming complexity: I think many MMORPGs use already existing "frameworks" and this code probably doesn't support the server across data. Hence, the effort to change this is never taken into consideration or is not even allowed.