Have you considered that America is a wealthy country, where anyone with a job even flipping burgers can buy a 150cc motorcycle and then take his girl on a date without a process that involves getting accosted by a paranoid schizophrenic?
You can basically buy a small motorcycle or scooter or fast e-bike on credit for the cost of maintaining a bus pass. It's only a rational choice for elderly or people with such mental or physical disabilities they can't maintain or operate similarly cheap alternatives. The end result is public transit gets dominated by hood rats, mentally ill, homeless, and a few elderly and people with disabilities, and due to the first amendment you can't stop the first couple classes from harassing the rest so as soon as a normal person gets their 50cc scooter or whatever similarly cheap other option fixed they go right back on that.
Sweden is also a wealthy country, even more here in Stockholm, people can lease cars for cheap, can buy scooters, etc., and public transport is still great: clean, reliable, covers a huge area since it's very sprawlwd, with almost no disturbances (in more than 10 years I can count on my digits the amount of times I've seen someone being mildly disturbing to others passengers). I only cycle and ride public transport here since I never cared (nor had to care) about getting a Swedish driver's licence.
The issue is not free speech, it's how your society educates people to be citizens.
If the US builds high density corridors supported by high frequency, reliable public transit connecting desirable destinations (housing with shopping, CBDs, etc), I'm willing to bet a lot that every social class will be represented on those public transit lines.
Yeah, great.. I was recently hit by a paranoid schizophrenic on a E scooter.. More logically he could have been denied access since he had plenty of public transportation options where he wouldn't have gone on to eventually maime people.
I don't have any reason to believe a paranoid schizophrenic capable of buying and maintaining a scooter is going to be any more persuaded to use public transit than anyone else. They are going to use alternatives for the same reason the rest of us do.
The ones using public transit are generally the ones with functional issues to the point they can't even get to that point of having a functional e scooter to crash.
Court systems persuade people based on weighing rights, necessities and probable harm. Reduce public transit and their decisions change, increase it and they may make incompetent pilot free zones.