They are now used extensively by homeless for a variety of activities.
Good, everytime a homeless person uses a public bathroom it is a net savings on health, safety and environmental impact because many of those people are denied access to anywhere to go take a shit and turns out people shitting everywhere isn't a great idea.
If some of the homeless are out of control and trash the bathroom... ok fine we are talking about people in the most tumultous and vulnerable positions in our society here. Make the bathroom like portlands public bathrooms; design them so they are hard to break and you can hose them down.
Nobody is not using the restroom by choice.
Places that smell like urine or excrement clearly don’t have enough restrooms and/or don’t get cleaned enough
It might finally be time to consider reopening them.