I've never watched any HP movies or engaged with any of the content but...
I feel obliged to add a little balance to this conversation as I do find some of the criticism to be overzealous.
First off, Kingsley is not the only black character in the series:
Secondly, I'm definitely not suggesting that either of the following examples is conclusive proof of 'appropriate diversity'(...?) in this fictional universe, but I am mindful of this:
Author says Noma Dumezweni is ‘best for the job’ in West End play Harry Potter and the Cursed Child
www.theguardian.com
And this:
Millions of fans around the world were yesterday digesting the news that one of the main characters in the Harry Potter novels, Albus Dumbledore, is gay.
www.theguardian.com
Both could be spun as being ‘baiting/appeasement’ through retrospective cynical eyes but, in reality, both were widely considered ultra-progressive at their respective times (particularly with Dumbledore - it was a
huge talking point, as silly as that may seem by modern standards). I’m also mindful that the casting of the Cursed Child was
long before everyone was applauding the casting in Netflix’s Bridgerton. To my mind, this does suggest that JK has explored diversity beyond nonchalantly naming a character 'Cho Chang'.
As for Cho Chang, I’m not an Asian woman so I can’t say I know how it would feel from that perspective. But I do question what name would be 'better', considering that the specific ethnicity of this person is never mentioned. Would a more conventional Asian name like Lei Wong have been better, or would it draw the same criticisms…? Or should she have had a conventional non-Asian namesake?
Likewise, I’m not Jewish, so I can’t say I know how it would feel from that perspective either. But, if the goblins are offensive for the reasons mentioned, could any fictional race of 'greedy persons' ever be acceptable? I can’t say that anti-semitism has ever crossed my mind with Harry Potter, nor have I ever looked at the appearance of the Goblins and thought anything about them seemed to suggested a Jewish appearance. I’ve never even heard of such comparisons before this thread. Granted, perhaps you could rummage through the bin of history and pick out a deliberately offensive piece of anti-Jewish propaganda where Jewish people are presented to look like ‘monsters’, but I don’t think it’s fair to deem any ‘comparable monster’ as deliberately offensive for that reason alone.
Finally, some broader considerations:
(I) Could the HP universe be more diverse? Yes, obviously it could be. It’s also obvious that many people in the UK (and outside of it) grow up in non-diverse environments. Are depictions of any non-diverse demographic inherently problematic, or just somewhat reflective of realities that can and do exist? Should everything that is not ‘mindfully engineered to be 100% immune to diversity criticism’ be deemed as ‘problematic’?
(II) These books, which are children’s books, are probably the first place that many children encounter issues of racism (‘mud bloods’) and forced labour (‘house elves’) in a digestible manner that is broadly appropriate for that age-group.
(III) Can wider conversations be had about the casting and portrayal of various races etc in consumable media? Yes, of course.
Despite this mini-essay, I’m not wishing to start lengthy dialogue on this either - just some food for though because, again, I just want to add some balance to the presented hypothesis that there are "massive problems” with the HP series itself.
Taking this back to theme parks, I also think that if if there was a widely held belief that there were such “massive unsolvable problems” with the series, we would not be seeing the franchise being built in the new park. Nobody wants a ‘Splash Mountain 2’.