UGC actually enforced this rule after one of the '92 matches where there was a lot of aliasing going on (I think saam aliasing as "evl are fucking retards" might have pushed it over the edge). It's kind of annoying when you have admins constantly telling you to get your players to change their names, so you have to constantly tell your players that they need their name to be proper, and they're all memeing and refuse to do it, but I understand why the rule is there.
Also, whenever Sigafoo casts, always has every player pre-aliased as their proper name, which granted how he's only one person and the EVL casting team was presumably more than one person, always amused me why they just didn't do that. I don't know how much work it is but i doubt it really is that much work.