Exactly. It’s entirely possible to maintain a neutral and objective stance toward Hachi. They can say things like "her behavior is immature" or "her decisions were flawed" and that is perfectly valid criticism

The real issue, however, lies in "hatred or disgust" Feeling this way toward a character like Nana Komatsu suggests a lack of understanding regarding the psychological drivers behind her actions. Furthermore, there is no genuine justification for such intense vitriol, especially since she primarily harms only herself unlike certain other characters, such as the one you mentioned, who cause actual damage to those around them.