It’s not “forbidden,” it’s a specific use that is allowed. “Playground @ Sunset Park” is acceptable. Every letter of known alphabets are acceptable but certain arrangements of them are not. " ツ" is acceptable but thrown into a title in an irrelevant manner is not. (Commence the war on ツ)
What came first, artists identifying their nom de plume with an “@-” tag for platforms utilizing tags to address user accounts or the tech bro platform? Do the artists tend to genuinely identify as @[name]? I know that in some of my circles I’ll introduce myself as Gendgi but I’ve never said “Hi I’m at Gendgi.”
What nation or group of nations supports your “free speech?” Because I’m guessing it doesn’t protect you from following rules established by a private company and how they choose to moderate their intellectual property.