That Hank Azaria has voiced Apu for so many decades, and that Apu is a stereotype is somewhat ... odd to consider in animation. Cartoon characters tend to be cartoony, especially in American animation. By "cartoony" we can say stereotyped.
But it depends on how these stereotypes are deployed. Take The Powerpuff Girls. Blossom is, as Cathy Cavadini joked, the bossy one of the girls. Tara Strong has spelled out that Bubbles wants to save the world but she wants to look cute while doing it, the bubbly blonde. Buttercup wants to fight. These characters work in the cartoon because we get to laugh with them more than we get to laugh at them.
But the controversy about Apu as an ethnic stereotype and being voiced by Azaria got me thinking ... animation is normally not an industry where this even becomes a controversy.
Who, exactly, has publicly complained for the record that Phil LaMarr voiced Samurai Jack? Nobody that I know of and nobody I would or could ever take seriously. LaMarr's turn as Jack was frankly iconic. I also loved what he did with Jon Stewart Green Lantern on Justice League. That was fantastic stuff.
Would people now wish to register a complaint that Mae Whitman doesn't look like a Pacific Islander enough to voice Katara from The Last Airbender? She was phenomenal in that role.
One of the better gags among the extras in earlier seasons of Archer was riffing on the idea of what might happen of Sterling Archer looked like H. Jon Benjamin, the voice actor who plays him, rather than his character design.
From within the animation industry, if you know about how often and how dramatically those who provide the voices for beloved or be-hated characters do not even remotely resemble the physical appearance of the characters then it can make sense why The Simpsons took the "shrug" approach that has been met with some bafflement or frustration. it may not seem like it was the "right" or appropriate response for The Simpsons crew to have but having been a fan of animation my whole life and knowing at least some of the production processes, that's something that I'm surprised hasn't gotten ... has it gotten any discussion?
For fans of animation a debating point might be suggesting that studios need to hire Crispin Freeman and Tara Strong less often as the default voices for cartoons not because they're bad (if anything they're both reliably fantastic) but because it dilutes the effectiveness of what they do if lazy voice-casting directors just keep going back to Freeman and Strong. Some voices are just a given, like Peter Cullen as Optimus Prime. Or I'd say Frank Welker as Megatron and Soundwave and Fred from Scooby Doo. I just can't really imagine anyone else voicing those roles. Though ... until I heard Matthew Lillard as Shaggy I never imagined anyone else could do that voice.
But then all these other characters I've mentioned from animated shows are not "just" stereotypes even if you could describe the characters by invoking stereotypes. Whereas, what very little I can remember about Apu is a stereotype and in that sense the criticisms made of Apu are very easy to understand. One of the arguments that has been presented is that, just to take Japanese characters as a for instance, I just named Samurai Jack but the odds that you could name at least a dozen other characters who are Japanese or of Japanese American lineage in a show that are not "just" stereotypes is fairly high.