So the argument against an interesting idea that has been implemented successfully in some localities is that there is an unrelated problem (homelessness) that

So the argument against an interesting idea that has been implemented successfully in some localities is that there is an unrelated problem (homelessness) that has also been addressed successfully in other places. I agree that potential problems should always be anticipated. But if the conclusion is "well we have homelessness so we can't offer a service that will be taken advantage of by homeless people in unintended ways" we can just as well agree that everyone with a six figure income move into a gated community and leave the rest of society to THE PURGE. The obvious conclusion for a self-respecting society should be "let's try free public transit and also throw money and mental health support at the homeless population until they don't exist any more."