Yeah, I totally agree that this is a multigenerational problem. And I totally get why you're resigned to it. It isn't your job to clean up a problem created by white people, and you having to do that work is just another burden of racism.

But personally, I plan to raise a ruckus like this whenever I get the chance. MLK made a strong argument for creating a "constructive tension" [1]. It was his theory that the necessary changes don't just happen, but require the discomfort of the people with the power to fix things. If my intern had wanted to let things lie, I certainly would have. But since he was ok with me reporting it, I saw it as my duty. To society certainly, but also to the company. They had a serious diversity effort and worked hard to give interns a good experience. I would have been negligent had I let an unconscious mistake from one employee undermine that.

Plus, as a white dude, it's easier for me to advocate for these changes. Not only because of my default privilege, but because I'm seen as a disinterested party. I never get accused of "playing the race card" or "misandry" when I come out against some racist or sexist nonsense. So I hope more white people will put their shoulders to the wheel here.

[1] https://en.wikipedia.org/wiki/Letter_from_Birmingham_Jail