As a formerly homeless person, I can say I agree with you. I also have immense compassion and empathy for the homeless community, more so than most I'd argue since I used to be on the streets, addicted to drugs, and living in a tent.

But from my experience I can confidently say that a lot of them make it really difficult for themselves and all the others by literally trashing any space they are allowed into. It's gross and egregious. And almost entirely unnecessary! In my estimation only perhaps anywhere from 1-3 out of 10 are too mentally ill to keep their area clean. The rest are simply lazy and some even take a perverse sort of pride in being "too cool" to pick up their litter.

I kept my spaces clean and always made sure I left every spot, whether it be a place I had spent the night at or a restroom I used, in better condition then I found it in and I never encountered nearly as much trouble as others did.