I think one of the points here is that, whilst having the ability the change your username on a somewhat regular basis: 1 week, 2 weeks, monthly, like you can in most games, isn't a be all and end all for players.
It does however add an element of freedom. It's also fun and a useful feature to have for a number of reasons.
It seems senseless to restrict this freedom and feature to such a degree as suggested.
Most gaming community's have little to issue with players renaming to something similar to someone they like or admire, or just for the lols. Whatever the reason, taking such measures for the sake of pacifying a select few who have presumably complained about this seems unjustified and unfair.
Why restrict this nice little element of freedom players have in a community that is so small.
In fact, if you change the renaming rule so that players can't change their name for at least 1 year, then this could have the exact opposite effect of which it intends to remedy.
Consider this, leading up to the new rule, player x changes their name to player y to look like or seem like he is player z, or something similar to player z, thereby "impersonating" player z right before the change occurs. This Player y will now be subject to player impersonation for an entire year. He will carry his so-called impersonated name for 1 whole year, leading players to think, or be confused as to whether player y is actually player z, when he is in fact player x.
As the current 1 month rule stands, player y can revert his name back to being who he is normally know as, that is player x. Thereby resolving any "confusion" some players may have surrounding his identity in a relatively short space of time.
That goes away if 1 month changes to 1 year.
(Not to mention the fact - as I keep stating - that players can check who players are by simply checking their name history)