I don't understand what the problem is with this manha

It's set in futuristic china and Korean fans didn't like that it was set in China so they were harrasing the manhwa author about it (cause this is a korean manhwa and not Chinese but is set in china) so the author decided to wrap the story up really early and not go any deeper jnto the story lines :(

I honestly don't understand this fury. A lot of Korean manga are set in China, and no one has ever criticized. Thanks for the explanation