At the risk of kicking a bee nest, I can see why. There are serious problems with Aboriginal communities across the general Perth area and of course in wider WA. Catching a train here even in the middle of the day is unpleasant or scary the majority of the time, at the very least at specific stations. People here have negative experience after negative experience with Indigenous Australians in the city and in the suburbs and they, like all of us, can become upset and judgemental as a result.
It is absolutely remarkable though how a good attitude can influence your experiences. I have seen fucking blatantly unaware racism from many people here towards the Indigenous, or people who seem intent on inciting things then pretending like they did nothing wrong. Almost lost my shit at this white lady on a train once who sat there judgementally staring down these two completely chill Aboriginal blokes for "drinking on the train" until they just started yelling at her, understandably in my opinion. If they were white she would've said jack shit ("I've worked with Indigenous communities before!"). If they were drinking bubble tea she would've said jack shit. Then people at the other end of the train hear that shit and what are they going to think? They gonna give the screaming Abos the benefit of the doubt? That was one of the most upsetting experiences of my life and to this day I regret not standing up for them and telling her to shut her fucking mouth, especially considering there's no way she would've fucking been the one dealing with shit when it hit the fan if they were as dodgy as she evidently thought they were.
At any rate, I've been to Sydney many times and never experienced the kind of violent or drunken or delinquent behaviour from Indigenous Australians that I see almost all the time in Perth city. Perhaps it has something to do with an underdeveloped cultural identity here given that there are far fewer Indigenous people in WA compared to the Eastern states, though quite a higher rate of Indigenous Australians against the state population. Maybe it's just people in Perth have treated them worse. I don't know. I'm aware of studies that indicate a strong sense of culture is positively correlated to self-reported levels of happiness and other wellbeing indicators. I think the honest and decent thing to do is to recognise Australia's role in precipitating these problems and fucking up the lives of Indigenous Australians which has undoubtedly filtered through the generations with very little offset, but also pretending like those problems don't exist is immeasurably naive and unhelpful.