I'd have to agree that this is just review bombing and can't possibly accurately represent consumer sentiment. This is not another Bud Light or Target fiasco, this movie is doing huge box office numbers,

https://variety.com/2023/film/news/little-mermaid-memorial-day-box-office-fast-x-disney-1235627238/

with people knowing it has a black Ariel. So the majority of consumers clearly don't actually care about this. This decision does not seem to have hurt them, even if I don't embrace this trend of changing characters genders/races that seems to be sweeping hollywood. I don't have young kids, so Disney doesn't care what I think. They pander to the values of parents of young children, which used to be christian, but are now woke progressive values.

I would strongly suspect the people review-bombing this movie did not actually see it, and are doing an act of political protest. Disney's target audience does not seem unhappy with this film.