You do know that people don't purposely change their name to "unknown", right? It happens sometimes when a players logs off their character.
You know what does "grind my gears" though? When children with anger issues use the anonymity of the internet to take out their frustration on innocent people. People who get pushed around in real life who seek refuge online to vent their misdirected rage all over forums, online games, and YouTube comment sections. The same kind of people you see on Classic who purposely block doors or PK people who are farming.