About re zero haters 
- 2021.07.21 18:03 (UTC+0)
This happens with most popular shows with few exceptions. It's because more people watch them basically. This means there is a larger pool of people to criticize it initially.
Critical voices are usually the loudest. A lot of people who like a show, but don't necessarily love it, won't bother with a review or with defending criticism of it.
On the other hand, people who dislike a show will more frequently give their opinion. People are more prone to talk about this sort of thing when they don't like it than when they do.
Other people read those reviews or hear other word of mouth before they see it, which colors their perception of the show.
After a while those criticisms take hold and other people parrot them. Others use hate for the show as a meta joke. Some people don't even watch the show and just parrot what they've heard about it, which is most often critical.
It's basically the Nickleback effect.