You're making it sound as though it's a petty issue, and for some it's not. People who are forced to rename will lose track of a lot of wider friends and acquaintances, that isn't a petty issue in an MMO. If they're attached to the name because it's one they've used in other games and makes them instantly recognisable, they lose their wider gaming identity. Doesnt help that a lot of people put their character names in their signatures on the forums, which opened up another avenue of copycatting. Not everyone is compaining, but this is an inconvenience to a lot of people, especially Guilds concerned about moving as a group, and it's fair for people to voice their concerns.
It is a petty issue in all honesty if people in guilds are worried about being unable to transfer and find their guildmates or even "friends" outside of the guild then perhaps they should communicate outside of this game which is a wonder of the internet by the way. As well they should have planned ahead when they first heard the news of this transfer By communicating with their guildmates and coordinating plans to do so which can easily be done outside of this game if these people are so important to you or anyone . We have known about this for more then a month now and it's pretty sad that everyone is in an uproar over this. Just as in real life friends come and go and unfortunately this is the same case. This solution was in demand and if people don't like what they are doing then too bad. it's important that they do and the way it's being done is just the reality of doing such a massive toon transfer. So either deal with what you demanded to happen or don't it doesn't matter this game will continue on.