I hate musicals, but I was bored on Netflix and decided to watch Annie because of the cast. I've seen the original Annie but I was never super passionate about it. Knew a couple songs and that was basically it. I just finished watching this one and I thought it was a nice movie. Unrealistic scenes (why would the fake parents keep on driving?) sure, but it's a kids movie. It was enjoyable and this is one of the first movies where I actually listened to all the songs. Loved it :D
It was rated low because a lot of people who didn't see it gave it a 1. Its a common pattern for certain types of movies. You can see it by looking at the vote distribution:
9 times out of 10, when the 1 votes are at least ~3x more than the 2 votes the movie also has minorities in most of the lead roles. Especially if you break out the votes by male versus female.
Its not 100%. Some movies legitimately polarize viewers. And as more people vote the effect is usually mitigated because there just aren't enough dedicated bigots. This movie is a little bit of an exception in that 26,250 votes is pretty large already.
It will be interesting to come back in a year and see how the rating has changed. Here's a current snapshot for posterity:
26250 IMDb users have given a weighted average vote of 5.3 / 10
So then by your logic, some voters gave this film a 10 just because it had a minority cast. I don't think anyone would believe that many people who actually saw this movie thought this was the best film they've ever seen. It goes both ways.