Especially viewed in its original context, introducing a new programming language (C) to a planet that wasn't quite as crowded with programming languages as it is today.
Since then it's just tradition. Feel free to leave it out. But it's iconic for a reason.
Moving goalposts around on the Hello World code golfing world has some 'consequences' - there's languages with built in hello world that try and get it printing with minimal code, and removing the comma, for example, would invalidate that hack.
It's always better to use contextual words in most examples.
edit: for more clarity this article (1) explains it quite well
Placeholder variables like i and j don't count! Foo, Baz, etc are annoying to read too, IMO.