After Ginny's quarrel with Max at the end of Season 1, their relationship changed dramatically, and Max's attitude towards her former friend turned into hostility.
Max continued to show her true colors in Season 2, but many viewers were unhappy with her development causing the character to be seriously criticized.
Hatred towards Max is related to her reactions to previous events. She felt betrayed, vented her anger on friends and seemed truly uncompromising. Max's feelings are generally understandable and justified, since she has always been honest and temperamental.
However, her reactions to some situations were surprising. Max was criticized for actions towards Abby who also hurt her. Despite any objective reasons, the resentment and anger went on too long for her feelings to be considered reasonable. In short, Max crossed the line. She was stubborn and all her dramatic and explosive reactions just intensified her conflict with former friends.
As for the situation with Ginny and Marcus, we may assume that Max was really worried about her brother and his feelings, but Ginny's potential betrayal should have been discussed with her first.
Max's reactions were violently negative, she didn’t try to understand the situation and didn’t want to listen to explanations. She focused on her feelings, without taking into account other people’s emotions and whatever was going on in their lives.
Fans’ dislike for Max can also be explained by the following. For illustrative purposes, let’s imagine having a friend like her. It seems to be very exhausting if everything always has to be about this person, and you must pander to their whims and make them feel good and never expect anything in return. Max sometimes seems to be a character with such personality traits.
In other words, the main complaint against Max is based on the fact that she is a real drama queen who was unable to deal with her negative feelings. In defense of Max, it can be noted that she was going through a transitional period. She had to learn how to cope with strong emotions while she was growing up and developing as a person. The good news is that friends eventually came to a reconciliation.
In Season 2, they finally put all the disagreements behind, but before that Max had managed to show her worst side.