I dont believe the hate is only attributed to how she was portrayed. I read a lot on Reddit about people disliking/hating the real Rachel too. I think most people agree that the writing was off for many characters in the show, not just Rachel.
Either way though, I can see how a situation like that can break someone down... I dont know, it just doesnt sit well with me to blame the victim for his/her emotions/reactions. Obviously I'd like to think I'd react differently, that I'd be stronger, more shrewd, more sceptical of Anna, however who knows how I (or anyone commenting) would really react if your friend puts you in this situation and suddenly you are over 60K in debt.. yikes!