Did they specifically express such a sentiment?
So, I think people are hating on hwayoung even though it's her sister who sent the nasty messages, because of how she faked/exaggerated her injury to skip a concert. In school, most if not all of us would have experienced that one slacker member in a project group. Such a slacker is usually detested. Ask yourself, would you be 100% forgiving and 0% angry at such a member? (Also, if I were the slacker in a group I would accept that the group hates me. I'd be surprised if they didn't. I would not complain about 'determination is not enough' or make lame excuses. But anyway.) These two scenarios are very similar. Hence people are hating her because her poor work ethic was the start of this whole controversy.