Yes, there will be people posting negative comments about events and/or characters that they dislike or disagree with in the series. Whether it has to do with characters, shipping, or how the creators decided to wirte the original series or the previous series people have been complaining about other peoples dislikes and disagreements with how things were written. This has happened especially with shipping. Users and contributors have been claiming to be very mature people by telling people what to type and what not to type because they are reading things that they don't want to hear. Those "mature" users/contributors will even make fun of those people for posting those types of comments. For example, someone will post a comment on disliking Mako or the Makorra ship then, someone replies "Here we go again...", "Stop the Mako Hate! ", or "Nobody cares who you ship." when there is really... no need to do so. Guess what, every person who walks the face of the Earth is entitled to and has every right to speak there own opinions. ALL of the comment sections are open for people to express their own feelings and opinions on how the series was written.
However, it is not okay for anyone to start leaving swear words, innopropriate language, harrassment of any kind, trolling etc. Now, those types of comments really shouldn't be acceptable. It's okay to hate a cartoon character but, it is most certainly not okay to shove hate into the faces of real life poeple. Hate is what caused wars throughout world history and it continues to tear this world apeart and it makes me sick. Unfortunately this world is and always will be filled with cold and cruel people and I am totally with the people who are against the rude commenters.