It's interesting that CCP chose this issue of impersonation as its "hill to die on". When you look at all the terrible things that Eve players have done, why is this issue the one that CCP moves to squelch?
I think it is because this issue has the greatest potential to break down trust in the game. Now, most people in Eve say "Trust no one." In reality, however, many of them do trust others. Trust is only way a group of people, a society, can build something larger. And Eve is very much about building things. It is very important for Eve to foster trust.
In a world where many of the "civilized" social norms do not apply, trust has to be earned. Trust can only be earned by building up a reputation over time. However, to take advantage of a reputation, an individual must be identifiable as the one who built that reputation. If someone else can easily pretend to be that individual, then you cannot rely on reputation and therefore cannot trust anyone.
If two players cannot trust each other, they have to interact through a third-party that they both trust. But if no player can be trusted, then players are forced to rely on the one third party which they can trust: the game itself.
We see this a lot in MMOs. Most trading is done through automated markets or auction houses. Thus neither player on both sides of the transaction need to trust each other. In WoW, when LFR came out, it soon became apparent that players could not trust each other to distribute loot fairly. Thus Blizzard had to step in, and implement a game system that could be trusted.
The less players trust each other, the more the game company has to intervene. The game company has to mediate the interaction and dictate how the interaction works.
And this is unfortunate, especially for sandbox play. If all interactions occur through game systems, the emergent behavior we prize never has a chance to develop. The games become less interesting and more static.
It would be interesting to see a game with even fewer system that act as a buffer between players. Consider a system where mail had to be delivered by other players. Or a game without automated markets. It would certainly be inconvenient. But this game is also more likely to give rise to unexpected styles of play.
Another interesting experiment would be a game system which cannot be trusted. For example, an unreliable Auction House or NPC merchants who sometimes steal the money from a sale. What systems would players evolve to cope? Maybe they would make many small orders and just take the expected loss. (More likely they would just quit and go to another game, though.)
MMOs need to foster a certain level of trust between their players. The less trust in the system, the more the game company itself has to intervene to reduce the necessity of that trust, and the less likely that interesting or inventive emergent behavior will evolve.