There is a very large and rampant amount of bad behavior well below the "jail time" threshold. Even then, the police can't be everywhere all of the time.

> There is a very large and rampant amount of bad behavior well below the "jail time" threshold.

Where? I don't see it in major cities I am in, and I take public transit regularly.

Then your city has much larger problem. In my city, public transport is as safe as anywhere else. That is how most people get to work. And kids to school.

> If you behave badly on public transit there's a real chance that you get the ultimate ban: jail time

In New York or San Francisco?