IRC isn’t a place, it’s a platform for speech for lots of diverse groups, some of which were/are racist. Saying IRC was/is racist is like saying the internet is racist.
... but it's also a true generalization, in the sense that if you throw a dart at a random IRC channel across all networks, you'll proabably hit one where the level of tolerated racism and sexism is at least "American standard."
> Saying IRC was/is racist is like saying the internet is racist