The law (which varied by municipality) was enforced against Food Not Bombs pop-up events as well as random people. It wasn't created to stop homeless encampments, trash or needles, because encampments don't just show up wherever someone gives out sandwiches. Homeless encampments happen under bridges, near railways, and other places where they can actually keep their stuff and won't get hassled by the cops.

Almost every other state in America deals with this the "traditional way", by having cops kick their ass until they move somewhere out of public view. Florida (and one or two other states) want to prevent them from coming to the state at all, so they're trying to make it harder to live there.