There is an imbalance in faced accountability. When a police officer assaults someone I want them to face legal consequences. They are now facing regular scrutiny from the public.
The problem is that repeat violent offenders, volatile drug users and scary people with mental disabilities, don't face scrutiny from the public on an organized level. They're babied by the legal system, and coddled by bleeding hearts when they do something terrible.
A result is that the general public hates these people, but is too scared to do anything. Instead, they attempt to live far away, drive everywhere, and laugh at the foolish people caught in the crossfire.
There is a reason I don't call violent people, or people that use drug users in confined spaces "vulnerable". It's because they're far less vulnerable that the child walking alone, or the woman taking the train/bus to work.
The real victims are the daily, normal, productive, none-violent users of transit that constantly face difficulties from these people. The biggest disagreement I'll face on this is from upper middle class men that likely own a car. I don't want to hear it.