Quoting Blair Waldorf (SuperKink):" I'm here to call out THIS smurfing smurf for being a complete bitch and going back on her offer to another ... [snip!] ... back on her offer for no good reason. WHO the SmUrf pulls the rug out from under someone when they're already down?! "
Eh I feel like there is probably a lot more to this story than what we see.
I think it's a human reaction to want to offer your home to someone when they're in need, but when the reality sets in that someone you met online will be staying in your house, or your husband/boyfriend/whoever isn't okay with it....then you look bad.
I think I'd have to know more about the story to be upset at her for backing out.
Obviously the girl was in need and it would have been a wonderful fix for her if she could stay with the other BG member, but do we know why she backed out? I think that would determine whether or not it's something to "hate" her over.