Russel T. Davies and David Tennant on “The Satan Pit.”
When he refers to his relationship with Rose, that’s something very tangible, very real, and something that he absolutely will always believe in.
So I want to just take a moment to really appreciate Rose, because a lot of fans give her flack due to her relationship with the Doctor and the fact that she gets everything handed to her in the show despite having a ‘flat’ personality compared to his other companions thus far in the show.
But when you really think about it, it wasn’t her beauty or intelligence that mattered to the Doctor. She goofs up a lot, and she’s not the brightest character. Nor is she very good at keeping the Doctor in line like Donna or Amy. Sure, at first she acts a bit shallow and is very wishy washy. But despite that nature of hers, there’s one thing she always stuck by. And that’s the Doctor.
Sure, he had fun with his other companions and they were loyal to him, but Rose was different from them because she let him be himself. She didn’t give him mixed messages, she knew how to give him the company he was always longing for. She wasn’t super intelligent, but she was fun and the two of them shared a lot of little dorky moments together. Her flaw was being a typical human being. But despite being that, she still stayed with the Doctor. And she always would if she could. She tore through the void between dimensions for him. She really, really loved him, and unlike Martha who pushed herself on him constantly, she gave him his space at let him come to her when he was ready. She knew of his loneliness and his fear of being alone, she knew that tragic pain he would have to feel when he outlived her, so I feel she kept her feelings available but only that. She wanted it to be his choice, and she would have been happy either way as long as she was there to make sure he wasn’t alone for as long as she could. Martha left him because she couldn’t handle the fact that she’d never be in a relationship with him, she didn’t understand why he wouldn’t and why he was hurting, she only told herself “he wont ever love me and it’s bad for me”. If Rose was faced with that issue, I don’t think she would have cared, because she loved him and their adventures so much and she knew that he needed her.
And when she was given the Metacrisis Doctor on the beach, that Doctor was the one who COULD tell her and COULD be with her. He was one who was ready and who wouldn’t have to suffer that pain, and even though she was happy with him it was clear she still felt just awful for the original Doctor… But she let him go.
That takes a lot to do, and for that… She is a good companion.