South Park, Simpsons, Family Guy and all the greats are packed full of racially-adventurous humour and that's part of what makes these shows great. Scottish, British, Indian, Japanese, Jewish, Muslim and virtually everyone is picked on.
They're equal opportunity offenders.
If you don't like it, that's your prerogative, but don't force your preferences on the rest of us.
As to why not have whites play Asians even in a cartoon when they can just as easily play space aliens and pink unicorns? The same reason we all hate Big Bang Theory, it leads to tired and insulting jokes based on shallow stereotypes. This is why Asians don't like Apu, because most of the jokes around him are based on lazy and frequently negative stereotypes. The jokes about space aliens and pink unicorns could also be lazy, but there's no space aliens or pink unicorns to get affected by them, fortunately. Remember that Nahasapeemapetilon isn't even a name in any culture, it's made up to sound funny to western audiences.
Apu is on the whole a very positive stereotype - a successful and responsible small business owner who's respected by his and contributes to his community.
Compare him to someone like Cletus who is a negative stereotype of white Southerners, portrayed as an extremely low IQ ignoramus. Or Kyle's cousin in South Park who's a negative stereotype of a Jew, portrayed as a hypersensitive money-grubber. And so on.
Your injury is nothing more than an imagined grievance.
"This is why Asians don't like"
Speak for yourself. You aren't a spokesperson for South Asians, and not all of them are on the same wokeness bandwagon.
This seems to belie the entire concept of fiction writing. Must that writer also be a straight married male with children and own a convenience store? Can a male writer write a book with female characters, or vice versa?
Hank literally agrees with me. Of course I'm not saying that in general, but in this specific case its absolutely the right thing to do.
I don't know what's special about this case. I mean I understand what's of special importance to you, but if writer <-> character matching is required here, I don't see what would prevent it from becoming a universalizable rule that would turn "write what you know" from a piece of hackneyed advice into a moral principle.