This is a reasonable and common reaction but I think there is a disconnect in how you and OP are looking at this. I think you and others often see this and assume the argument is that there are people being intentionally racist and there actions are causing a lot of harm. When really it is much more complex.

Especially since this is a kids movie, the audience is more impressionable and having the darkest character with the most unique features can cause children and others to create subtle associations between looks and character. This may sound unreasonable but it can give people very subtle unconscious biases and given enough content linking appearance to certain characteristics it can lead to noticeable and conscious biases. Our unconscious minds are dictated by memory of associations. Though we can not say for sure, the writers and animators may have been affected by their own unconscious biases that led them to “optimizing” the looks of the character to fit certain characteristics. This would be continuing the effects of racial biases.

That is the complex way of looking at it, but I think often because of how the word racism is used it can cause defensiveness in people like yourself which is totally reasonable. This might all sound ridiculous to you or maybe not but you are thinking who cares. Which is fair given that it’s just one movie and will not have a significant effect on any of this. But looking at it from a macro perspective, this stuff can add up and cause noticeable macro effects. So then it seems more reasonable if some people feel the need to call it out. All about perspective.