Moffat didn’t write Rose, Martha, or Donna. In the few episodes he wrote that these characters were in, there are very obvious differences from the characters RTD created and definitely a lot more classism, sexism, and racism going on.
Let’s talk about Irene. She was brilliant, sexy, and NEARLY outwitted Sherlock… but wait we can’t have her beat our hero! No, despite the fact that ACD’s original story ended with Irene besting Sherlock, Moffat decided to end his story with Sherlock saving Irene because she’s just not smart enough to outwit him. Her agency is completely lost. Yay, what a great strong female character!
Wait but what about River? Oh right, her entire story was written around the Doctor which means she has very little agency as well. Her whole life centers around either her love for or hatred of the Doctor. Even though she becomes an archaeologist and professor, we never get to see any of that and it is never implied that it’s very important in her life. No, instead all that matters is that she was born and raised to kill the Doctor, gave all her regenerations to save him, is consistently written off and ignored by him, and is definitely far more in love with him than he is with her. Think about the series from her perspective. Pretty fucked up, don’t you think? Oh and then there’s the whole River-is-obviously-bisexual thing, which is utter bullshit because she is never seen breaking out of the heterosexual little circle that Moffat has written all of his stories into, and the only suggestion of it is a throwaway line about some people she doesn’t even care about. Great representation, Moffat. Seems more like pandering and even fetishising to me. OH AND LET’S NOT FORGET HER DEATH. The Doctor ACTUALLY PLANS HER DEATH OUT. She has no say in it! The most she can do is tie him up and strap herself in, and from then on her life is in his hands. And he ignores her wish and saves her consciousness in a fucking COMPUTER. And we’re supposed to believe she’s happy living in the virtual world (which the story presented as insufficient) forever and ever with some people she doesn’t really know? That entire ending was so horribly executed.
And Amy. Let’s see, once again we have a character with NO AGENCY. S5 is okay, but as soon as we move into S6 there is such a mess with her character she hardly even counts as a character. She isn’t even present for much of the series, as she’s being held in a creepy chamber growing the baby that’s going to kill the Doctor. Then she loses her child and her loss is almost immediately forgotten. The next episode leaves absolutely no opportunity for anger or mourning. Instead, the story completely ignores the pain she should have been feeling at first losing her child and then finding her grown up, along with anger at the Doctor for not giving a fuck. S6 Amy functions primarily as a plot device. I couldn’t even watch most of S7 but the fact that her name on the gravestone is Amelia WIlliams is frustrating considering they spent most of two series reinforcing the idea that her name is Amy Pond and she chose it and that’s who she is.
Clara… we haven’t seen enough of her to be able to really tell, but so far she seems like another cookie cutter feisty mysterious woman that doesn’t take the Doctor’s shit that Moffat loves so much.
And Molly. She hardly even exists on the show until Sherlock notices her and how she can be useful to him. Even so, she’s mostly presented as a woman with a silly crush on a man who will never love her. Granted, she is shown to be smart and kind, but she’s also a supporting character which means we don’t get a lot of development for her at all.
You can say all you want that sometimes people get in shitty situations and that people lose control of their lives etc etc but when it comes down to it, this is scripted fiction. The writers choose what to do with their characters. And what they write is very telling about what they care about. Intentional or not, putting marginalised people on the outskirts of your stories shows that you don’t care about them, because either it’s subconscious and you don’t even notice (yay privilege) or it’s deliberate and therefore fucked up.
tl;dr Moffat writes shitty storylines for his cookie cutter women and does them a huge disservice with his lack of interest in developing them.