There is a distinct difference between a joke and making fun of someone’s personal appearance because it’s a sport Whites have engaged in for a few hundred years. It’s only a joke when all parties can laugh about it. Doubt you’ll EVER find any Black person laughing about blackface. Besides, White people do blackface in their private settings, which also makes it not a joke — it’s about degrading and disrespecting a Black person’s looks. The entire history of how racist and derogatory is EVERYWHERE if White people would read history other than their own.
What White people call “childish” or a “joke” is seen as such by them because they aren’t the butt of the jokes or racism.
If Black people had a party where all the Black people imitated everything we found undesirable or unattractive about White people, secretly — I’m sure Black people wouldn’t be able to claim being childish, joking, or PC. There would be hell to pay.
The problem isn’t about PC. The problem is White people gives zero fucks about what offends non-white people because they are the majority.