I'll say that this is less an issue with amazon and more an issue with the overall culture. Anecdotally, I've noticed a move from score based metrics to binary

I'll say that this is less an issue with amazon and more an issue with the overall culture. Anecdotally, I've noticed a move from score based metrics to binary like/dislike based metrics. Thus, reviews also take a binary 5 star: I loved it. or 1 star: I didn't approach.