The alt-right launched a kind of online counter-offensive against it, with particular focus and attention on the diverse cast. They made a big show of driving down fan reviews of rotten tomatoes, imdb, metacritic, etc. They harassed the young asian-american actress from the film to the point where she removed all of her instagram posts… bullshit like that. They latched onto the divided fan-response to the movie and ratcheted it up to eleven, and injected their racist, sexist nonsense into it at every opportunity. It was gross.
They kinda tried to do it with Black Panther, too, but that was substantially less successful. Not sure why, but I suspect it was because BP was pretty universally credited with being pretty good, so the neckbeard fuckboys had less cover to hide behind while they slung their crap.