I know this will be an unpopular opinion, but I think that part of Dorinda's issue with Tinsley is that Tinsley hasn't been completely truthful about her relationship with Scott. I wonder if Dorinda knew that Tinsley and Scott were seeing each other (off and on) from the start of filming and Tinsley was always denying it, so lying to them all. I think that Dorinda, at this point, is just frustrated with Tinsley. I could be completely off base, but I've been wondering about this for the past few weeks, trying to find a valid reason for Dorinda going so hard for Tinsley.
I'm not a fan of Tinsley's - I find her immature and vapid. I hate the way she acts like a 16 year old - from being thrilled at being told she looks just like Barbie to the screeching. I don't think she is as sweet and innocent as she appears to be. She knows how to play the game to appear sweet and innocent - she is probably the only true socialite among these so-called ladies. Yes, she is fairly kind and adopting her two dogs from China was a wonderful thing, but I also think that Tinsley can be calculating when it comes to how she wants people to see her.