It's unfortunate, but one problem with free public transport absent other changes is that then it becomes de facto free shelter, which degrades the service for people using it as transport.
Another commenter already made the same observation. See reply there.
>it becomes de facto free shelter
So? Let it.
If people need shelter, it's a shame we are building a ballroom instead of shelter.
That wouldn't be an issue if we also provided shelter to the most distressed people in our society. As if we don't have the technology to build housing on the cheap. Our lack of communal will to help fellow people is a real shame.