I couldn't root for Harding after conspiring against Kerrigan. A background of abuse is not a valid pretext to kneecap someone innocent.
I sympathize for the trauma she endured when younger but I believe strongly in the value of good sportsmanship and she violated that on an extreme level.
I don't think the point of the movie is to promote "rooting for" anyone. Hence the cultural reference in the film's title. The aim of the movie is to cultivate a level of empathy toward and understanding of others.