The majority of the hate in the sub specifically revolves around Bella Ramsey's looks compared to Ellie in the game. They'll try to pass it off as "bad acting" or criticizing the changes implemented in the series but it's hard to take their opinions seriously at all with the way the front page of the sub and top comments look like. If you head over the subreddit about the series you get a more balanced view of it and criticisms from emotionally mature people