If you read a lot of Sutcliffe's interviews and stuff, the fact some of them were working in the sex trade didnt really come into it mostly. He just found what he called 'likely victims' by them being alone walking at night generally. That aspect of it was almost entirely the media and Police's making
This is true and some of his early victims, who survived, were attacked away from urban and city centre areas, and nowhere near red light areas, but I'm not sure the police and media were wilfully ignoring that. As I said in a PP, the police and especially in such a high crime area as WY would not have been aware the cases were linked. That wasn't understood until later.
PS was using some of the busiest road networks in Europe and unfortunately this meant he was able to hide and cover his crimes within that. WY has a population of millions of people. Linking crimes across a huge urban area like this was not always that easy
I'm not excusing the behaviour of some police, but I'm just trying to explain the area. If he had been committing these crimes in a rural area, the crimes would have stood out more, been linked, and PS would have probably been noticed a lot earlier, especially on more rural roads at night.
PS was a lorry driver. Unfortunately he would have been very well aware of the road networks in WY and aware of how those roads were policed