No, I think you absolutely got the point. One can argue whether the Pizza Hut “rippin & dippin” commercial is racist - I have no problem with that. But you CAN’T say that it’s O.K. simply because there are some black people who actually talk like that. “Some of them really talk like that” is not an excuse for stereotyping a group. Back in the first half of the 20th Century, when it was common to portray blacks as charicatures and use blatant stereotypes, I have no doubt that you could have found real black people who actually did say things like “Ah sure 'nuff gwana do dat, boss” or Chinese people who actually said “Me so solly”, or whatever. Does that mean it’s not offensive? Absolutely not.
It’s offensive when it’s used to put people down. I’ve been called “white boy” in a tone that left no doubt that I was not being complimented in even the slightest way.
The intent is everything, really. If you’re making a period piece, then being historically accurate is just being accurate, assuming that you’re really being accurate, and not just jumping on a broad generalization because it’s easier.
Putting someone on the air with a thick Chinese accent is just that. Are we supposed to say that it’s bad to have an accent? Thank God I don’t have to try to speak Chinese, because it would be literally unintelligible. It’s not a character flaw to have an accent.
Then entire reason that Pizza Hut put that accent on the air is because it is viewed as “cool” these days, not to make fun of anyone at all. So in the absence of any derogatory meaning, it can’t be racist.