"River Song, Amy Pond and Clara Oswald are exactly the same sexy, sassy female character Moffat loves."
I think you mean
"River Song, Amy Pond and Clara Oswald -despite having vastly different story arcs, personalities, jobs, hobbies, lifestyles, relationships and personal philosophies- are all represented as being body positive. We have very little representation in the media of women who think they are attractive, and the ones who do are more often than not villains and antagonists. Therefore I have chosen to amplify that single shared trait River, Amy and Clara have and reduce all their other characteristics, so I can make them into the perfect strawmen for my argument that Moffat can’t write women. In reality it proves I have little to no textual analysation skills, and can’t overcome my societal programming in regards to the dominant discourse of women who hate their appearance are not only good and kind, but secretly beautiful all along, while women who actually like their appearance must be shallow and self absorbed and therefore not worthy of consideration as legitimate individuals in their own right."
everyone has said and done problematic things in their lifetime. that’s a result of the society we live in, not necessarily a reflection of their character.
what is a reflection of their character is how they react to being informed of the negativity within their behavior and statements, and whether or not they choose to change their behavior.