So being homeless isnt the problem, mudering isnt exclusive to homeless people. Drugs and prostitution aren't problems. Cities not having adequate public serivces like bathrooms is a problem.
We have littering rules, we as a society don't find it important. Why is styrofoam or cans OK. If you thinks drugs are a problem because they are a source of litter you should also think take out and portable food and other things people litter with are a problem?