Because there seems to be a lot of players who don’t like/understand why the idea of having a nonsensical name (with a bunch of random letters and numbers) would be against the rules, I’m going to explain why on one of my servers (as an example) it is prohibited. (I get players questioning me about that rule all the time).
First, it’s a rule (and if you don’t like it, then like any other rule, you don’t have to play there). Second, generally, I find that many hackers/griefers come on for a brief time and just type in names with that type of nonsense because it either is difficult to remember, difficult to reference, or just exerts the least amount of energy when creating a name that they will ditch as soon as they are done griefing the server. Much like when a person does not change their profile picture to a custom one (which is another rule I have), you get people who make minimal effort to create igns that are unremarkable… so that they can wreak havoc and have the best chance to get away with it.
And before everyone chimes in and says that “just because they have a name that makes no sense doesn’t mean they are all hackers or griefers or bad players, etc”, I want to say OF COURSE it doesn’t apply to everyone. No one is saying that it does. However, it does and has applied to some, and if an owner wants to create a rule that lessens the possibility of someone doing bad things on their server, GO FOR IT. After all, as I first stated, if it’s the owner’s rule, you need to abide by it. If you don’t want to, then choose another server. Very simple.