Sadly homelessness and mental health issues get push around until they find somewhere the less resistance. Because of the NA “public transport is for the poor” mindset it means there’s no political capital from handling that issue in public transport. If a homeless sleeps on a street, a cop will spawn within 5 minutes to kick him to the side walk (because obviously pedestrians don’t mind). Hell in Montreal when it’s super cold outside the police implicitly told to be more lenient with homeless people sleeping in the subway otherwise because they have nowhere to go and outside they will die (homeless dying from cold weather happens every year here)

What you are saying is correct, and, it’s a legitimate reason to dislike public transport. I’m just nuancing that it’s not an issue inherent to public transport it’s inherent to the choices we make as a society (hide unpleasant people for the comfort of a class of people). Some would even say it’s directly because we value cars more than human lives which seems hyperbolic at first but the more you think about it…