The Wiz!

So I'm super excited for the live action version of the Wiz because it was one of my favorite musicals growing up. Naturally, I've been reading about it leading up to the premiere and there have been several people posting about how the all-black cast is "racist" and how Blacks would be upset if there was an all-white version of the Wiz (side note: there was and it's called The Wizard of Oz).

So I'm genuinely curious why some White people view POCs things as "racist", but are fine with all-White productions as the norm. Keeping in mind that POCs had to create separate spaces for themselves after being denied access to opportunities due to racism.

Any thoughts?