|“||I grew in Thatcher’s Britain. We would look out of the window every morning to make sure the bitch hadn’t put Daleks on the streets yet.||”|
— Warren Ellis
Margaret "Eyes of Josef Stalin, Mouth of Marylin Monroe" Thatcher was a politician, writer, and 8th level arch-fiend. Literally every major creative voice associated with Doctor Who in particular and British sci-fi and comedy in general has a raging, throbbing, steel hard hateboner for her. There is functionally no end to the amount of quote mining one could engage in. Cartmel became a writer with the hopes of bringing her government down. RTD's intention was that the audience would turn on Harriet Jones and demand the Doctor defeat her just for repeating one of Thatcher's acts. Steven Moffat concluded that a genocidal dictator who tore time apart in order to take over the universe was a better Prime Minister of Britain than she was, and nobody came to her defense.
In other words, the program and her have a somewhat divisive history.