One of the most important ways to make a train network that doesn't suck is to aggressively police the sorts of antisocial behavior on public transit committed by the most marginalized people in society. There are a lot of political barriers to actually doing this, not the least of which is that it necessarily involves incarcerating more marginalized people, using more police violence against marginalized people, and inevitably having the police kill more marginalized people.

If you're reaction to Daniel Penny's killing of Jordan Neely on the New York City Subway isn't "Daniel Penny was a hero, Jordan Neely should have been incarcerated rather than allowed to freely exist on the train, and everyone involved in Penny's prosecution should be thrown out of positions of power", then you can't actually make the train network not suck.