Thats a bad argument... There are plenty of places that rules in place to prevent "homeless tent encampments" from being a thing. The same laws that prevent you from camping in city parks. Thats a bad example...
Obviously you haven't been to Portland lately. Any plot of land that doesn't have an overnight closure turns into a homeless camp.
Lets look at an open park that can't be easily locked up.
How much easier is it to enforce no one in the park past $10 than no camping in the park.