American cities are poorly legislated and suffer from a tragedy of the commons when it comes to basic public needs like restrooms. We have deep seated issues that keep us from being able to have nice things like that.
Edit: no, once. The McDonald's in the Netherlands on the A16 highway, right after the Belgian border has paid toilets, even for customers. It's a disgrace.
I'd rather pay for toilets and have them be clean, than free and dirty.