At least she's trying to teach them, she's not apathetic toward them. She comes from a place of passion, but her wrongdoing in the eyes of many is that she's not PC enough.
I don't think she has a problem with this, honestly, and I don't know if it's a culture Polish thing, or a Muay Thai thing, but she's of the school that iron sharpens iron, and not to be a therapist in there and make someone feel special to get them to try their best.
Maybe she isn't such a sweetheart, but more like a tough chick. It's gonna piss off ALOT of people, especially in American culture, where you gotta be cool with everyone or you are roundabout demonized.