I lived in Mexico City in the 70's and I remember how sexist everything was, so it's not hard to believe that the first female officers had to put up with dismissive, sexist attitudes from the male officers. I was also a police officer in America in the 80's and things hadn't changed that much in ten years. Even today most people outside of policing have the belief that being an officer is all about how strong you are and how fast you can run and little to do with your intelligence and your ability to communicate with anyone in the public. Women are great at this and are more likely to get a person to cooperate than want to fight them. But if they have to fight they can. Women have a place in the criminal justice system despite what some people think.
As far as the show, female officers were forced to wear those ridiculous skirts which obviously made their jobs even harder. The women are looking into details of the case that the detectives are ignoring in order to get an arrest for a serial killer, regardless if that person didn't do it. This actually happened a lot in the 1970's when the technology didn't exist (in America either) to tie someone to a crime. Much of it was circumstantial. I have just finished episode 3 and I find it intriguing enough to keep watching. The sexism is hard to watch as it brings up bad memories, but at least it's realistic.