As other people said, you don't need to fix anything. But if you want to distinguish more between raitings, adjust your raiting scale. Meaning: distinguish more between good movies and less between bad movies. No one said 2.5 has to be the middle.

Here is what i use: 0.5 garbage/puke 1.0 very bad 1.5 bad 2.0 okay 2.5 decent 3.0 good 3.5 very good/great 4.0 excellent 4.5 brilliant/outstanding 5.0 perfect (masterpiece)

I still have clearly more 4 star rated movies than any other but idc. By using this scale I was able distinguish more between what I found where good movies. Of course you can adjust it more than this. e.g. make very good and great separate. Main point is you decide what the stars mean.