Yeah. To be fair, any time you're trying to rate personal preferences on a fixed scale, there are going to be huge subjectivity issues if only because personal preferences are themselves quite subjective. Ten-point scales tend to have it a bit worse because most people are inculcated for literally decades in a grading system where 7/10 is average and 5/10 is awful, which creates conflict with people adopt a flat linear scale where 5/10 is average and 2/10 awful. Five-star scales with half-star granularity tend to be a bit better, even if the actual numbers are identical (2.5 stars = 5/10), because it helps divorce the rating scale from that grading system and makes it more likely that the reviewers are using a single standard for what the numbers mean. Or, at least, something closer to a single standard; you still have to worry about people who, say, calibrate against Mars of Destruction (which I've never heard of, but I assume to be poor) versus calibrating versus something like Gankutsuou (which was decent enough, but had an art style that could occasionally induce headaches).
Then you run into things like acquiescence bias (the tendency to agree rather than disagree, even outside of peer-influenced biases) or its converse, extreme responding (the tendency to vote to extremes rather than medians), and the aforementioned peer-influenced biases, all of which aren't as easy to eliminate...